2022 |
Zhou, J; Zhang, C; Shi, L; Chen, X; Kim, T S; Gyeon, M; Chen, J; Wang, J; Yu, L; Wang, X; Kang, K; Orgiu, E; Samorì, P; Watanabe, K; Taniguchi, T; Tsukagoshi, K; Wang, P; Shi, Y; Li, S Non-invasive digital etching of van der Waals semiconductors Article de journal Dans: Nat. Commun., 13 (1844), 2022. @article{Zhou2022, title = {Non-invasive digital etching of van der Waals semiconductors}, author = {J. Zhou and C. Zhang and L. Shi and X. Chen and T. S. Kim and M. Gyeon and J. Chen and J. Wang and L. Yu and X. Wang and K. Kang and E. Orgiu and P. Samorì and K. Watanabe and T. Taniguchi and K. Tsukagoshi and P. Wang and Y. Shi and S. Li}, url = {https://doi.org/10.1038/s41467-022-29447-6}, year = {2022}, date = {2022-04-05}, journal = {Nat. Commun.}, volume = {13}, number = {1844}, abstract = {The capability to finely tailor material thickness with simultaneous atomic precision and non-invasivity would be useful for constructing quantum platforms and post-Moore microelectronics. However, it remains challenging to attain synchronized controls over tailoring selectivity and precision. Here we report a protocol that allows for non-invasive and atomically digital etching of van der Waals transition-metal dichalcogenides through selective alloying via low-temperature thermal diffusion and subsequent wet etching. The mechanism of selective alloying between sacrifice metal atoms and defective or pristine dichalcogenides is analyzed with high-resolution scanning transmission electron microscopy. Also, the non-invasive nature and atomic level precision of our etching technique are corroborated by consistent spectral, crystallographic, and electrical characterization measurements. The low-temperature charge mobility of as-etched MoS2 reaches up to 1200 cm2 V−1s−1, comparable to that of exfoliated pristine counterparts. The entire protocol represents a highly precise and non-invasive tailoring route for material manipulation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The capability to finely tailor material thickness with simultaneous atomic precision and non-invasivity would be useful for constructing quantum platforms and post-Moore microelectronics. However, it remains challenging to attain synchronized controls over tailoring selectivity and precision. Here we report a protocol that allows for non-invasive and atomically digital etching of van der Waals transition-metal dichalcogenides through selective alloying via low-temperature thermal diffusion and subsequent wet etching. The mechanism of selective alloying between sacrifice metal atoms and defective or pristine dichalcogenides is analyzed with high-resolution scanning transmission electron microscopy. Also, the non-invasive nature and atomic level precision of our etching technique are corroborated by consistent spectral, crystallographic, and electrical characterization measurements. The low-temperature charge mobility of as-etched MoS2 reaches up to 1200 cm2 V−1s−1, comparable to that of exfoliated pristine counterparts. The entire protocol represents a highly precise and non-invasive tailoring route for material manipulation. |
Ippolito, S; Samorì, P Defect Engineering Strategies Toward Controlled Functionalization of Solution-Processed Transition Metal Dichalcogenides Article de journal Dans: Small Sci., 2 (4), p. 2100122, 2022. @article{Ippolito2022, title = {Defect Engineering Strategies Toward Controlled Functionalization of Solution-Processed Transition Metal Dichalcogenides}, author = {S. Ippolito and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smsc.202100122}, year = {2022}, date = {2022-04-01}, journal = {Small Sci.}, volume = {2}, number = {4}, pages = {2100122}, abstract = {Solution-processed transition metal dichalcogenides (TMDs) are attracting unceasing attention owing to their wide-ranging portfolio of physicochemical properties, making them prime candidates for low-cost and real-life applications in (opto)electronics, (bio)sensing, and energy-related technologies. The performance of TMD-based devices is strictly interconnected with the inherent features and quality of the materials, which should be tuned in view of their ultimate application. In this regard, the device performance is hitherto undermined by the presence of structural defects inherited from both the bulk systems and the exfoliation procedures. To overcome this limitation, a notable research effort has been devoted to the development of molecular strategies taking advantage of the defective nature of solution-processed TMDs, in order to meticulously tailor their physicochemical properties and expand the range of applicability. In this perspective, some of the most enlightening advances regarding the functionalization approaches exploiting TMD structural defects are presented, introducing the typical “imperfections” encountered in 2D crystal lattices (with different dimensionality, ranging from 0D to 2D) as well as discussing their in situ/ex situ generation methods. Finally, we highlight the future directions, challenges, and opportunities of defect engineering in TMDs by offering guidelines to boost the progress of 2D materials science and related technology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Solution-processed transition metal dichalcogenides (TMDs) are attracting unceasing attention owing to their wide-ranging portfolio of physicochemical properties, making them prime candidates for low-cost and real-life applications in (opto)electronics, (bio)sensing, and energy-related technologies. The performance of TMD-based devices is strictly interconnected with the inherent features and quality of the materials, which should be tuned in view of their ultimate application. In this regard, the device performance is hitherto undermined by the presence of structural defects inherited from both the bulk systems and the exfoliation procedures. To overcome this limitation, a notable research effort has been devoted to the development of molecular strategies taking advantage of the defective nature of solution-processed TMDs, in order to meticulously tailor their physicochemical properties and expand the range of applicability. In this perspective, some of the most enlightening advances regarding the functionalization approaches exploiting TMD structural defects are presented, introducing the typical “imperfections” encountered in 2D crystal lattices (with different dimensionality, ranging from 0D to 2D) as well as discussing their in situ/ex situ generation methods. Finally, we highlight the future directions, challenges, and opportunities of defect engineering in TMDs by offering guidelines to boost the progress of 2D materials science and related technology. |
Han, B; Zhao, Y; Ma, C; Wang, C; Tian, X; Wang, Y; Hu, W; Samorì, P Asymmetric Chemical Functionalization of Top-Contact Electrodes: Tuning the Charge Injection for High-Performance MoS2 Field-Effect Transistors and Schottky Diodes Article de journal Dans: Adv. Mater., 34 (2109445), 2022. @article{Han2022, title = {Asymmetric Chemical Functionalization of Top-Contact Electrodes: Tuning the Charge Injection for High-Performance MoS2 Field-Effect Transistors and Schottky Diodes}, author = {B. Han and Y. Zhao and C. Ma and C. Wang and X. Tian and Y. Wang and W. Hu and P. Samorì}, editor = {Wiley}, url = {https://doi.org/10.1002/adma.202109445}, year = {2022}, date = {2022-03-24}, journal = {Adv. Mater.}, volume = {34}, number = {2109445}, abstract = {The fabrication of high-performance (opto-)electronic devices based on 2D channel materials requires the optimization of the charge injection at electrode–semiconductor interfaces. While chemical functionalization with chemisorbed self-assembled monolayers has been extensively exploited to adjust the work function of metallic electrodes in bottom-contact devices, such a strategy has not been demonstrated for the top-contact configuration, despite the latter being known to offer enhanced charge-injection characteristics. Here, a novel contact engineering method is developed to functionalize gold electrodes in top-contact field-effect transistors (FETs) via the transfer of chemically pre-modified electrodes. The source and drain Au electrodes of the molybdenum disulfide (MoS2) FETs are functionalized with thiolated molecules possessing different dipole moments. While the modification of the electrodes with electron-donating molecules yields a marked improvement of device performance, the asymmetric functionalization of the source and drain electrodes with different molecules with opposed dipole moment enables the fabrication of a high-performance Schottky diode with a rectification ratio of ≈103. This unprecedented strategy to tune the charge injection in top-contact MoS2 FETs is of general applicability for the fabrication of high-performance (opto-)electronic devices, in which asymmetric charge injection is required, enabling tailoring of the device characteristics on demand.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The fabrication of high-performance (opto-)electronic devices based on 2D channel materials requires the optimization of the charge injection at electrode–semiconductor interfaces. While chemical functionalization with chemisorbed self-assembled monolayers has been extensively exploited to adjust the work function of metallic electrodes in bottom-contact devices, such a strategy has not been demonstrated for the top-contact configuration, despite the latter being known to offer enhanced charge-injection characteristics. Here, a novel contact engineering method is developed to functionalize gold electrodes in top-contact field-effect transistors (FETs) via the transfer of chemically pre-modified electrodes. The source and drain Au electrodes of the molybdenum disulfide (MoS2) FETs are functionalized with thiolated molecules possessing different dipole moments. While the modification of the electrodes with electron-donating molecules yields a marked improvement of device performance, the asymmetric functionalization of the source and drain electrodes with different molecules with opposed dipole moment enables the fabrication of a high-performance Schottky diode with a rectification ratio of ≈103. This unprecedented strategy to tune the charge injection in top-contact MoS2 FETs is of general applicability for the fabrication of high-performance (opto-)electronic devices, in which asymmetric charge injection is required, enabling tailoring of the device characteristics on demand. |
Yao, Y; Chen, Y; Wang, K; Turetta, N; Vitale, S; Han, B; Wang, H; Zhang, L; Samorì, P A robust vertical nanoscaffold for recyclable, paintable, and flexible light-emitting devices Article de journal Dans: Sci. Adv., 8 (eabn2225), 2022. @article{Yao2022, title = {A robust vertical nanoscaffold for recyclable, paintable, and flexible light-emitting devices}, author = {Y. Yao and Y. Chen and K. Wang and N. Turetta and S. Vitale and B. Han and H. Wang and L. Zhang and P. Samorì}, editor = {Science}, url = {https://doi.org/10.1126/sciadv.abn2225}, year = {2022}, date = {2022-03-11}, journal = {Sci. Adv.}, volume = {8}, number = {eabn2225}, abstract = {Organic light-emitting devices are key components for emerging opto- and nanoelectronics applications including health monitoring and smart displays. Here, we report a foldable inverted polymer light-emitting diode (iPLED) based on a self-suspended asymmetrical vertical nanoscaffold replacing the conventional sandwich-like structured LEDs. Our empty vertical-yet-open nanoscaffold exhibits excellent mechanical robustness, proven by unaltered leakage current when applying 1000 cycles of 40-kilopascal pressure loading/unloading, sonication, and folding, with the corresponding iPLEDs displaying a brightness as high as 2300 candela per square meter. By using photolithography and brush painting, arbitrary emitting patterns can be generated via a noninvasive and mask-free process with individual pixel resolution of 10 μm. Our vertical nanoscaffold iPLED can be supported on flexible polyimide foils and be recycled multiple times by washing and refilling with a different conjugated polymer capable of emitting light of different color. This technology combines the traits required for the next generation of high-resolution flexible displays and multifunctional optoelectronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organic light-emitting devices are key components for emerging opto- and nanoelectronics applications including health monitoring and smart displays. Here, we report a foldable inverted polymer light-emitting diode (iPLED) based on a self-suspended asymmetrical vertical nanoscaffold replacing the conventional sandwich-like structured LEDs. Our empty vertical-yet-open nanoscaffold exhibits excellent mechanical robustness, proven by unaltered leakage current when applying 1000 cycles of 40-kilopascal pressure loading/unloading, sonication, and folding, with the corresponding iPLEDs displaying a brightness as high as 2300 candela per square meter. By using photolithography and brush painting, arbitrary emitting patterns can be generated via a noninvasive and mask-free process with individual pixel resolution of 10 μm. Our vertical nanoscaffold iPLED can be supported on flexible polyimide foils and be recycled multiple times by washing and refilling with a different conjugated polymer capable of emitting light of different color. This technology combines the traits required for the next generation of high-resolution flexible displays and multifunctional optoelectronics. |
Chen, Y; Yao, Y; Turetta, N; Samorì, P Vertical organic transistors with short channels for multifunctional optoelectronic devices Article de journal Dans: J. Mater. Chem. C, , 10 , p. 2494–2506, 2022. @article{Chen2021b, title = {Vertical organic transistors with short channels for multifunctional optoelectronic devices}, author = {Y. Chen and Y. Yao and N. Turetta and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1tc05055a}, year = {2022}, date = {2022-02-21}, journal = {J. Mater. Chem. C, }, volume = {10}, pages = {2494–2506}, abstract = {Organic semiconductors are functional (macro)molecules with tunable physical properties that can be processed as mechanically flexible films over large areas via printing and other solution-based casting methods. Their unique characteristics make them ideal active components for the fabrication of novel flexible, low-power, ultra-light and high-performance devices such as displays, memories and sensors. Compared with planar field-effect transistors, vertical transistors emerged as a cheap and up-scalable solution for the fabrication of devices with nanoscale-sized active channels. The latter offers access to higher current densities at low operating voltages and thus to transition frequencies higher than planar organic transistors. As a result, the vertical organic transistor (VOT) design represents an ideal platform for applications requiring fast operating speeds with reduced power consumption, such as phototransistors and light-emitting devices. In fact, the future development of inexpensive and wearable smart devices depends on the ability to fabricate devices that can operate at low voltages as fast switching units while keeping size and manufacturing costs as low as possible. In this Perspective, we examine the most enlightening works on the development of multifunctional VOTs reported during the last decade and we discuss the challenges and opportunities to expand these strategies towards the technological implementation of VOTs in the next generation of opto-electronics and photonics technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organic semiconductors are functional (macro)molecules with tunable physical properties that can be processed as mechanically flexible films over large areas via printing and other solution-based casting methods. Their unique characteristics make them ideal active components for the fabrication of novel flexible, low-power, ultra-light and high-performance devices such as displays, memories and sensors. Compared with planar field-effect transistors, vertical transistors emerged as a cheap and up-scalable solution for the fabrication of devices with nanoscale-sized active channels. The latter offers access to higher current densities at low operating voltages and thus to transition frequencies higher than planar organic transistors. As a result, the vertical organic transistor (VOT) design represents an ideal platform for applications requiring fast operating speeds with reduced power consumption, such as phototransistors and light-emitting devices. In fact, the future development of inexpensive and wearable smart devices depends on the ability to fabricate devices that can operate at low voltages as fast switching units while keeping size and manufacturing costs as low as possible. In this Perspective, we examine the most enlightening works on the development of multifunctional VOTs reported during the last decade and we discuss the challenges and opportunities to expand these strategies towards the technological implementation of VOTs in the next generation of opto-electronics and photonics technologies. |
Ricciardulli, A G; Wang, Y; Yang, S; Samorì, P Two-Dimensional Violet Phosphorus: A p-Type Semiconductor for (Opto)electronics Article de journal Dans: J. Am. Chem. Soc., 144 , p. 3660–3666, 2022. @article{Ricciardulli2022, title = {Two-Dimensional Violet Phosphorus: A p-Type Semiconductor for (Opto)electronics}, author = {A. G. Ricciardulli and Y. Wang and S. Yang and P. Samorì}, editor = {ACS}, url = {https://doi.org/10.1021/jacs.1c12931}, year = {2022}, date = {2022-02-18}, journal = {J. Am. Chem. Soc.}, volume = {144}, pages = {3660–3666}, abstract = {The synthesis of novel two-dimensional (2D) materials displaying an unprecedented composition and structure via the exfoliation of layered systems provides access to uncharted properties. For application in optoelectronics, a vast majority of exfoliated 2D semiconductors possess n-type or more seldom ambipolar characteristics. The shortage of p-type 2D semiconductors enormously hinders the extensive engineering of 2D devices for complementary metal oxide semiconductors (CMOSs) and beyond CMOS applications. However, despite the recent progress in the development of 2D materials endowed with p-type behaviors by direct synthesis or p-doping strategies, finding new structures is still of primary importance. Here, we report the sonication-assisted liquid-phase exfoliation of violet phosphorus (VP) crystals into few-layer-thick flakes and the first exploration of their electrical and optical properties. Field-effect transistors based on exfoliated VP thin films exhibit a p-type transport feature with an Ion/Ioff ratio of 104 and a hole mobility of 2.25 cm2 V–1 s–1 at room temperature. In addition, the VP film-based photodetectors display a photoresponsivity (R) of 10 mA W–1 and a response time down to 0.16 s. Finally, VP embedded into CMOS inverter arrays displays a voltage gain of ∼17. This scalable production method and high quality of the exfoliated material combined with the excellent optoelectronic performances make VP an enticing and versatile p-type candidate for next-generation more-than-Moore (opto)electronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The synthesis of novel two-dimensional (2D) materials displaying an unprecedented composition and structure via the exfoliation of layered systems provides access to uncharted properties. For application in optoelectronics, a vast majority of exfoliated 2D semiconductors possess n-type or more seldom ambipolar characteristics. The shortage of p-type 2D semiconductors enormously hinders the extensive engineering of 2D devices for complementary metal oxide semiconductors (CMOSs) and beyond CMOS applications. However, despite the recent progress in the development of 2D materials endowed with p-type behaviors by direct synthesis or p-doping strategies, finding new structures is still of primary importance. Here, we report the sonication-assisted liquid-phase exfoliation of violet phosphorus (VP) crystals into few-layer-thick flakes and the first exploration of their electrical and optical properties. Field-effect transistors based on exfoliated VP thin films exhibit a p-type transport feature with an Ion/Ioff ratio of 104 and a hole mobility of 2.25 cm2 V–1 s–1 at room temperature. In addition, the VP film-based photodetectors display a photoresponsivity (R) of 10 mA W–1 and a response time down to 0.16 s. Finally, VP embedded into CMOS inverter arrays displays a voltage gain of ∼17. This scalable production method and high quality of the exfoliated material combined with the excellent optoelectronic performances make VP an enticing and versatile p-type candidate for next-generation more-than-Moore (opto)electronics. |
Yu, X; Fu, S; Mandal, M; Yao, X; Liu, Z; Zheng, W; Samorì, P; Narita, A; Müllen, K; Andrienko, D; Bonn, M; Wang, H I Tuning interfacial charge transfer in atomically precise nanographene–graphene heterostructures by engineering van der Waals interactions Article de journal Dans: J. Chem. Phys., 156 (074702), 2022. @article{Yu2022, title = {Tuning interfacial charge transfer in atomically precise nanographene–graphene heterostructures by engineering van der Waals interactions}, author = {X. Yu and S. Fu and M. Mandal and X. Yao and Z. Liu and W. Zheng and P. Samorì and A. Narita and K. Müllen and D. Andrienko and M. Bonn and H. I. Wang}, editor = {API}, url = {https://doi.org/10.1063/5.0081074}, year = {2022}, date = {2022-02-15}, journal = {J. Chem. Phys.}, volume = {156}, number = {074702}, abstract = {Combining strong light absorption and outstanding electrical conductivity, hybrid nanographene–graphene (NG–Gr) van der Waals heterostructures (vdWHs) represent an emerging material platform for versatile optoelectronic devices. Interfacial charge transfer (CT), a fundamental process whose full control remains limited, plays a paramount role in determining the final device performance. Here, we demonstrate that the interlayer vdW interactions can be engineered by tuning the sizes of bottom-up synthesized NGs to control the interfacial electronic coupling strength and, thus, the CT process in NG–Gr vdWHs. By increasing the dimensions of NGs from 42 to 96 sp2 carbon atoms in the polyaromatic core to enhance the interfacial coupling strength, we find that the CT efficiency and rate in NG–Gr vdWHs display a drastic increase of one order of magnitude, despite the fact that the interfacial energy driving the CT process is unfavorably reduced. Our results shed light on the CT mechanism and provide an effective knob to tune the electronic coupling at NG–Gr interfaces by controlling the size-dependent vdW interactions. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Combining strong light absorption and outstanding electrical conductivity, hybrid nanographene–graphene (NG–Gr) van der Waals heterostructures (vdWHs) represent an emerging material platform for versatile optoelectronic devices. Interfacial charge transfer (CT), a fundamental process whose full control remains limited, plays a paramount role in determining the final device performance. Here, we demonstrate that the interlayer vdW interactions can be engineered by tuning the sizes of bottom-up synthesized NGs to control the interfacial electronic coupling strength and, thus, the CT process in NG–Gr vdWHs. By increasing the dimensions of NGs from 42 to 96 sp2 carbon atoms in the polyaromatic core to enhance the interfacial coupling strength, we find that the CT efficiency and rate in NG–Gr vdWHs display a drastic increase of one order of magnitude, despite the fact that the interfacial energy driving the CT process is unfavorably reduced. Our results shed light on the CT mechanism and provide an effective knob to tune the electronic coupling at NG–Gr interfaces by controlling the size-dependent vdW interactions. |
Turetta, N; Stoeckel, M -A; de Oliveira, Furlan R; Devaux, F; Greco, A; Cendra, C; Gullace, S; Gicevičius, M; Chattopadhyay, B; Liu, J; Schweicher, G; Sirringhaus, H; Salleo, A; Bonn, M; Backus, E H G; Geerts, Y H; Samorì, P High-Performance Humidity Sensing in π-Conjugated Molecular Assemblies through the Engineering of Electron/Proton Transport and Device Interfaces Article de journal Dans: J. Am. Chem. Soc., 144 , p. 2546–2555, 2022. @article{Turetta2022, title = {High-Performance Humidity Sensing in π-Conjugated Molecular Assemblies through the Engineering of Electron/Proton Transport and Device Interfaces}, author = {N. Turetta and M.-A. Stoeckel and R. Furlan de Oliveira and F. Devaux and A. Greco and C. Cendra and S. Gullace and M. Gicevičius and B. Chattopadhyay and J. Liu and G. Schweicher and H. Sirringhaus and A. Salleo and M. Bonn and E. H. G. Backus and Y. H. Geerts and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/jacs.1c10119}, year = {2022}, date = {2022-02-07}, journal = {J. Am. Chem. Soc.}, volume = {144}, pages = {2546–2555}, abstract = {The development of systems capable of responding to environmental changes, such as humidity, requires the design and assembly of highly sensitive and efficiently transducing elements. Such a challenge can be mastered only by disentangling the role played by each component of the responsive system, thus ultimately achieving high performance by optimizing the synergistic contribution of all functional elements. Here, we designed and synthesized a novel [1]benzothieno[3,2-b][1]benzothiophene derivative equipped with hydrophilic oligoethylene glycol lateral chains (OEG-BTBT) that can electrically transduce subtle changes in ambient humidity with high current ratios (>104) at low voltages (2 V), reaching state-of-the-art performance. Multiscale structural, spectroscopical, and electrical characterizations were employed to elucidate the role of each device constituent, viz., the active material’s BTBT core and OEG side chains, and the device interfaces. While the BTBT molecular core promotes the self-assembly of (semi)conducting crystalline films, its OEG side chains are prone to adsorb ambient moisture. These chains act as hotspots for hydrogen bonding with atmospheric water molecules that locally dissociate when a bias voltage is applied, resulting in a mixed electronic/protonic long-range conduction throughout the film. Due to the OEG-BTBT molecules’ orientation with respect to the surface and structural defects within the film, water molecules can access the humidity-sensitive sites of the SiO2 substrate surface, whose hydrophilicity can be tuned for an improved device response. The synergistic chemical engineering of materials and interfaces is thus key for designing highly sensitive humidity-responsive electrical devices whose mechanism relies on the interplay of electron and proton transport.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of systems capable of responding to environmental changes, such as humidity, requires the design and assembly of highly sensitive and efficiently transducing elements. Such a challenge can be mastered only by disentangling the role played by each component of the responsive system, thus ultimately achieving high performance by optimizing the synergistic contribution of all functional elements. Here, we designed and synthesized a novel [1]benzothieno[3,2-b][1]benzothiophene derivative equipped with hydrophilic oligoethylene glycol lateral chains (OEG-BTBT) that can electrically transduce subtle changes in ambient humidity with high current ratios (>104) at low voltages (2 V), reaching state-of-the-art performance. Multiscale structural, spectroscopical, and electrical characterizations were employed to elucidate the role of each device constituent, viz., the active material’s BTBT core and OEG side chains, and the device interfaces. While the BTBT molecular core promotes the self-assembly of (semi)conducting crystalline films, its OEG side chains are prone to adsorb ambient moisture. These chains act as hotspots for hydrogen bonding with atmospheric water molecules that locally dissociate when a bias voltage is applied, resulting in a mixed electronic/protonic long-range conduction throughout the film. Due to the OEG-BTBT molecules’ orientation with respect to the surface and structural defects within the film, water molecules can access the humidity-sensitive sites of the SiO2 substrate surface, whose hydrophilicity can be tuned for an improved device response. The synergistic chemical engineering of materials and interfaces is thus key for designing highly sensitive humidity-responsive electrical devices whose mechanism relies on the interplay of electron and proton transport. |
Wang, Can; de Oliveira, Rafael Furlan; Jiang, Kaiyue; Zhao, Yuda; Turetta, Nicholas; Ma, Chun; Han, Bin; Zhang, Haiming; Tranca, Diana; Zhuang, Xiaodong; Chi, Lifeng; Ciesielski, Artur; Samorì, Paolo Boosting the electronic and catalytic properties of 2D semiconductors with supramolecular 2D hydrogen-bonded superlattices Article de journal Dans: Nature communications, 13 (510), 2022. @article{Wang2022, title = {Boosting the electronic and catalytic properties of 2D semiconductors with supramolecular 2D hydrogen-bonded superlattices}, author = { Can Wang and Rafael Furlan de Oliveira and Kaiyue Jiang and Yuda Zhao and Nicholas Turetta and Chun Ma and Bin Han and Haiming Zhang and Diana Tranca and Xiaodong Zhuang and Lifeng Chi and Artur Ciesielski and Paolo Samorì }, editor = {Nature communication}, url = {https://www.nature.com/articles/s41467-022-28116-y}, year = {2022}, date = {2022-01-26}, journal = {Nature communications}, volume = {13}, number = {510}, abstract = {The electronic properties of two-dimensional semiconductors can be strongly modulated by interfacing them with atomically precise self-assembled molecular lattices, yielding hybrid van der Waals heterostructures (vdWHs). While proof-of-concepts exploited molecular assemblies held together by lateral unspecific van der Waals interactions, the use of 2D supramolecular networks relying on specific non-covalent forces is still unexplored. Herein, prototypical hydrogen-bonded 2D networks of cyanuric acid (CA) and melamine (M) are self-assembled onto MoS2 and WSe2 forming hybrid organic/inorganic vdWHs. The charge carrier density of monolayer MoS2 exhibits an exponential increase with the decreasing area occupied by the CA·M unit cell, in a cooperatively amplified process, reaching 2.7 × 1013 cm−2 and thereby demonstrating strong n-doping. When the 2D CA·M network is used as buffer layer, a stark enhancement in the catalytic activity of monolayer MoS2 for hydrogen evolution reactions is observed, outperforming the platinum (Pt) catalyst via gate modulation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The electronic properties of two-dimensional semiconductors can be strongly modulated by interfacing them with atomically precise self-assembled molecular lattices, yielding hybrid van der Waals heterostructures (vdWHs). While proof-of-concepts exploited molecular assemblies held together by lateral unspecific van der Waals interactions, the use of 2D supramolecular networks relying on specific non-covalent forces is still unexplored. Herein, prototypical hydrogen-bonded 2D networks of cyanuric acid (CA) and melamine (M) are self-assembled onto MoS2 and WSe2 forming hybrid organic/inorganic vdWHs. The charge carrier density of monolayer MoS2 exhibits an exponential increase with the decreasing area occupied by the CA·M unit cell, in a cooperatively amplified process, reaching 2.7 × 1013 cm−2 and thereby demonstrating strong n-doping. When the 2D CA·M network is used as buffer layer, a stark enhancement in the catalytic activity of monolayer MoS2 for hydrogen evolution reactions is observed, outperforming the platinum (Pt) catalyst via gate modulation. |
Zhao, Y; Gobbi, M; Hueso, L E; Samorì, P Molecular Approach to Engineer Two-Dimensional Devices for CMOS and beyond-CMOS Applications Article de journal Dans: Chem. Rev., 122 , p. 50-131, 2022. @article{Zhao2022, title = {Molecular Approach to Engineer Two-Dimensional Devices for CMOS and beyond-CMOS Applications}, author = {Y. Zhao and M. Gobbi and L. E. Hueso and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acs.chemrev.1c00497}, year = {2022}, date = {2022-01-12}, journal = {Chem. Rev.}, volume = {122}, pages = {50-131}, abstract = {Two-dimensional materials (2DMs) have attracted tremendous research interest over the last two decades. Their unique optical, electronic, thermal, and mechanical properties make 2DMs key building blocks for the fabrication of novel complementary metal–oxide–semiconductor (CMOS) and beyond-CMOS devices. Major advances in device functionality and performance have been made by the covalent or noncovalent functionalization of 2DMs with molecules: while the molecular coating of metal electrodes and dielectrics allows for more efficient charge injection and transport through the 2DMs, the combination of dynamic molecular systems, capable to respond to external stimuli, with 2DMs makes it possible to generate hybrid systems possessing new properties by realizing stimuli-responsive functional devices and thereby enabling functional diversification in More–than–Moore technologies. In this review, we first introduce emerging 2DMs, various classes of (macro)molecules, and molecular switches and discuss their relevant properties. We then turn to 2DM/molecule hybrid systems and the various physical and chemical strategies used to synthesize them. Next, we discuss the use of molecules and assemblies thereof to boost the performance of 2D transistors for CMOS applications and to impart diverse functionalities in beyond–CMOS devices. Finally, we present the challenges, opportunities, and long-term perspectives in this technologically promising field.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two-dimensional materials (2DMs) have attracted tremendous research interest over the last two decades. Their unique optical, electronic, thermal, and mechanical properties make 2DMs key building blocks for the fabrication of novel complementary metal–oxide–semiconductor (CMOS) and beyond-CMOS devices. Major advances in device functionality and performance have been made by the covalent or noncovalent functionalization of 2DMs with molecules: while the molecular coating of metal electrodes and dielectrics allows for more efficient charge injection and transport through the 2DMs, the combination of dynamic molecular systems, capable to respond to external stimuli, with 2DMs makes it possible to generate hybrid systems possessing new properties by realizing stimuli-responsive functional devices and thereby enabling functional diversification in More–than–Moore technologies. In this review, we first introduce emerging 2DMs, various classes of (macro)molecules, and molecular switches and discuss their relevant properties. We then turn to 2DM/molecule hybrid systems and the various physical and chemical strategies used to synthesize them. Next, we discuss the use of molecules and assemblies thereof to boost the performance of 2D transistors for CMOS applications and to impart diverse functionalities in beyond–CMOS devices. Finally, we present the challenges, opportunities, and long-term perspectives in this technologically promising field. |
Montes-García, V; Samorì, P Janus 2D materials via asymmetric molecular functionalization Article de journal Dans: Chem. Sci., 13 , p. 315–328, 2022. @article{Montes-García2022, title = {Janus 2D materials via asymmetric molecular functionalization}, author = {V. Montes-García and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1sc05836c}, year = {2022}, date = {2022-01-01}, journal = {Chem. Sci.}, volume = {13}, pages = {315–328}, abstract = {Janus two-dimensional materials (2DMs) are a novel class of 2DMs in which the two faces of the material are either asymmetrically functionalized or are exposed to a different local environment. The diversity of the properties imparted to the two opposing sides enables the design of new multifunctional materials for applications in a broad variety of fields including opto-electronics, energy storage, and catalysis. In this perspective, we summarize the most enlightening experimental methods for the asymmetric chemical functionalization of 2DMs with tailored made (macro)molecules by means of a supratopic binding (one side) or antaratopic binding (two sides) process. We describe the emergence of unique electrical and optical characteristics resulting from the asymmetric dressing of the two surfaces. Representative examples of Janus 2DMs towards bandgap engineering, enhanced photoresponse and photoluminescence are provided. In addition, examples of Janus 2DMs for real applications such as energy storage (batteries and supercapacitors) and generation (photovoltaics), opto-electronics (field-effect transistors and photodetectors), catalysis, drug delivery, self-healing materials, chemical sensors and selective capture and separation of small molecules are also described. Finally, we discuss the future directions, challenges, and opportunities to expand the frontiers of Janus 2DMs towards technologies with potential impact in environmental science and biomedical applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Janus two-dimensional materials (2DMs) are a novel class of 2DMs in which the two faces of the material are either asymmetrically functionalized or are exposed to a different local environment. The diversity of the properties imparted to the two opposing sides enables the design of new multifunctional materials for applications in a broad variety of fields including opto-electronics, energy storage, and catalysis. In this perspective, we summarize the most enlightening experimental methods for the asymmetric chemical functionalization of 2DMs with tailored made (macro)molecules by means of a supratopic binding (one side) or antaratopic binding (two sides) process. We describe the emergence of unique electrical and optical characteristics resulting from the asymmetric dressing of the two surfaces. Representative examples of Janus 2DMs towards bandgap engineering, enhanced photoresponse and photoluminescence are provided. In addition, examples of Janus 2DMs for real applications such as energy storage (batteries and supercapacitors) and generation (photovoltaics), opto-electronics (field-effect transistors and photodetectors), catalysis, drug delivery, self-healing materials, chemical sensors and selective capture and separation of small molecules are also described. Finally, we discuss the future directions, challenges, and opportunities to expand the frontiers of Janus 2DMs towards technologies with potential impact in environmental science and biomedical applications. |
Martin, C; Jonckheere, D; Coutino-Gonzalez, E; Smolders, S; Bueken, B; Marquez, C; Krajnc, A; Willhammar, T; Kennes, K; Fenwick, O; Richard, F; Samorì, P; Mali, G; Hofkens, J; Roeffaers, M B J; Vos, De D E Metal–biomolecule frameworks (BioMOFs): a novel approach for “green” optoelectronic applications Article de journal Dans: Chem. Commun., 58 , p. 677–680, 2022. @article{Martin2022, title = {Metal–biomolecule frameworks (BioMOFs): a novel approach for “green” optoelectronic applications}, author = {C. Martin and D. Jonckheere and E. Coutino-Gonzalez and S. Smolders and B. Bueken and C. Marquez and A. Krajnc and T. Willhammar and K. Kennes and O. Fenwick and F. Richard and P. Samorì and G. Mali and J. Hofkens and M. B. J. Roeffaers and D. E. De Vos}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1cc05214d}, year = {2022}, date = {2022-01-01}, journal = {Chem. Commun.}, volume = {58}, pages = {677–680}, abstract = {In this study, a water-stable microcrystalline bioMOF was synthesized, characterized, and loaded with silver ions or highly emissive rare earth (RE) metals such as Eu3+/Tb3+. The obtained materials were used as active layers in a proof-of-concept sustainable light-emitting device, highlighting the potential of bioMOFs in optoelectronic applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, a water-stable microcrystalline bioMOF was synthesized, characterized, and loaded with silver ions or highly emissive rare earth (RE) metals such as Eu3+/Tb3+. The obtained materials were used as active layers in a proof-of-concept sustainable light-emitting device, highlighting the potential of bioMOFs in optoelectronic applications. |
2021 |
Peng, H; Huang, S; Tranca, D; Richard, F; Baaziz, W; Zhuang, X; Samorì, P; Ciesielski, A Quantum Capacitance through Molecular Infiltration of 7,7,8,8-Tetracyanoquinodimethane in Metal–Organic Framework/Covalent Organic Framework Hybrids Article de journal Dans: ACS Nano, 15 , p. 18580–18589, 2021. @article{Peng2021, title = {Quantum Capacitance through Molecular Infiltration of 7,7,8,8-Tetracyanoquinodimethane in Metal–Organic Framework/Covalent Organic Framework Hybrids}, author = {H. Peng and S. Huang and D. Tranca and F. Richard and W. Baaziz and X. Zhuang and P. Samorì and A. Ciesielski}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsnano.1c09146}, year = {2021}, date = {2021-11-15}, journal = {ACS Nano}, volume = {15}, pages = {18580–18589}, abstract = {Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been extensively investigated during the last two decades. More recently, a family of hybrid materials (i.e., MOF@COF) has emerged as particularly appealing for gas separation and storage, catalysis, sensing, and drug delivery. MOF@COF hybrids combine the unique characteristics of both MOF and COF components and exhibit peculiar properties including high porosity and large surface area. In this work, we show that the infiltration of redox-active 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules into the pores of MOF@COF greatly improves the characteristics of the latter, thereby attaining high-performance energy storage devices. Density functional theory (DFT) calculations were employed to guide the design of a MOF@COF-TCNQ hybrid with the TCNQ functional units incorporated in the pores of MOF@COF. To demonstrate potential application of our hybrids, the as-synthesized MOF@COF-TCNQ hybrid has been employed as an active material in supercapacitors. Electrochemical energy storage analysis revealed outstanding supercapacitor performance, as evidenced by a specific areal capacitance of 78.36 mF cm–2 and a high stack volumetric energy density of 4.46 F cm–3, with a capacitance retention of 86.4% after 2000 cycles completed at 0.2 A cm–2. DFT calculation results strongly indicate that the high capacitance of MOF@COF-TCNQ has a quantum capacitance origin. Our liquid-phase infiltration protocol of MOF@COF hybrids with redox-active molecules represents a efficacious approach to design functional porous hybrids.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been extensively investigated during the last two decades. More recently, a family of hybrid materials (i.e., MOF@COF) has emerged as particularly appealing for gas separation and storage, catalysis, sensing, and drug delivery. MOF@COF hybrids combine the unique characteristics of both MOF and COF components and exhibit peculiar properties including high porosity and large surface area. In this work, we show that the infiltration of redox-active 7,7,8,8-tetracyanoquinodimethane (TCNQ) molecules into the pores of MOF@COF greatly improves the characteristics of the latter, thereby attaining high-performance energy storage devices. Density functional theory (DFT) calculations were employed to guide the design of a MOF@COF-TCNQ hybrid with the TCNQ functional units incorporated in the pores of MOF@COF. To demonstrate potential application of our hybrids, the as-synthesized MOF@COF-TCNQ hybrid has been employed as an active material in supercapacitors. Electrochemical energy storage analysis revealed outstanding supercapacitor performance, as evidenced by a specific areal capacitance of 78.36 mF cm–2 and a high stack volumetric energy density of 4.46 F cm–3, with a capacitance retention of 86.4% after 2000 cycles completed at 0.2 A cm–2. DFT calculation results strongly indicate that the high capacitance of MOF@COF-TCNQ has a quantum capacitance origin. Our liquid-phase infiltration protocol of MOF@COF hybrids with redox-active molecules represents a efficacious approach to design functional porous hybrids. |
Lucherelli, M A; Qian, X; Weston, P; Eredia, M; Zhu, W; Samorì, P; Gao, H; Bianco, A; von dem Bussche, A Boron Nitride Nanosheets Can Induce Water Channels Across Lipid Bilayers Leading to Lysosomal Permeabilization Article de journal Dans: Adv. Mater., 33 (2103137), 2021. @article{Lucherelli2021, title = {Boron Nitride Nanosheets Can Induce Water Channels Across Lipid Bilayers Leading to Lysosomal Permeabilization}, author = {M. A. Lucherelli and X. Qian and P. Weston and M. Eredia and W. Zhu and P. Samorì and H. Gao and A. Bianco and A. von dem Bussche}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adma.202103137}, year = {2021}, date = {2021-11-11}, journal = {Adv. Mater.}, volume = {33}, number = {2103137}, abstract = {Abstract While the interaction between 2D materials and cells is of key importance to the development of nanomedicines and safe applications of nanotechnology, still little is known about the biological interactions of many emerging 2D materials. Here, an investigation of how hexagonal boron nitride (hBN) interacts with the cell membrane is carried out by combining molecular dynamics (MD), liquid-phase exfoliation, and in vitro imaging methods. MD simulations reveal that a sharp hBN wedge can penetrate a lipid bilayer and form a cross-membrane water channel along its exposed polar edges, while a round hBN sheet does not exhibit this behavior. It is hypothesized that such water channels can facilitate cross-membrane transport, with important consequences including lysosomal membrane permeabilization, an emerging mechanism of cellular toxicity that involves the release of cathepsin B and generation of radical oxygen species leading to cell apoptosis. To test this hypothesis, two types of hBN nanosheets, one with a rhomboidal, cornered morphology and one with a round morphology, are prepared, and human lung epithelial cells are exposed to both materials. The cornered hBN with lateral polar edges results in a dose-dependent cytotoxic effect, whereas round hBN does not cause significant toxicity, thus confirming our premise. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract While the interaction between 2D materials and cells is of key importance to the development of nanomedicines and safe applications of nanotechnology, still little is known about the biological interactions of many emerging 2D materials. Here, an investigation of how hexagonal boron nitride (hBN) interacts with the cell membrane is carried out by combining molecular dynamics (MD), liquid-phase exfoliation, and in vitro imaging methods. MD simulations reveal that a sharp hBN wedge can penetrate a lipid bilayer and form a cross-membrane water channel along its exposed polar edges, while a round hBN sheet does not exhibit this behavior. It is hypothesized that such water channels can facilitate cross-membrane transport, with important consequences including lysosomal membrane permeabilization, an emerging mechanism of cellular toxicity that involves the release of cathepsin B and generation of radical oxygen species leading to cell apoptosis. To test this hypothesis, two types of hBN nanosheets, one with a rhomboidal, cornered morphology and one with a round morphology, are prepared, and human lung epithelial cells are exposed to both materials. The cornered hBN with lateral polar edges results in a dose-dependent cytotoxic effect, whereas round hBN does not cause significant toxicity, thus confirming our premise. |
Urbanos, F J; Gullace, S; Samorì, P Field-effect-transistor-based ion sensors: ultrasensitive mercury(II) detection via healing MoS2 defects Article de journal Dans: Nanoscale, 13 , p. 19682–19689, 2021. @article{Urbanos2021, title = {Field-effect-transistor-based ion sensors: ultrasensitive mercury(II) detection via healing MoS2 defects}, author = {F. J. Urbanos and S. Gullace and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1nr05992k}, year = {2021}, date = {2021-11-09}, journal = {Nanoscale}, volume = {13}, pages = {19682–19689}, abstract = {The contamination of water with heavy metal ions represents a harsh environmental problem resulting from societal development. Among various hazardous compounds, mercury ions (Hg2+) surely belong to the most poisonous ones. Their accumulation in the human body results in health deterioration, affecting vital organs and eventually leading to chronic diseases, and, in the worst-case scenario, early death. High selectivity and sensitivity for the analyte of choice can be achieved in chemical sensing using suitable active materials capable of interacting at the supramolecular level with the chosen species. Among them, 2D transition metal dichalcogenides (TMDCs) have attracted great attention as sensory materials because of their unique physical and chemical properties, which are highly susceptible to environmental changes. In this work, we have fabricated MoS2-based field-effect transistors (FETs) and exploited them as platforms for Hg2+ sensing, relying on the affinity of heavy metal ions for both point defects in TMDCs and sulphur atoms in the MoS2 lattice. X-ray photoelectron spectroscopy characterization showed both a significant reduction of the defectiveness of MoS2 when exposed to Hg2+ with increasing concentration and a shift in the binding energy of 0.2 eV suggesting p-type doping of the 2D semiconductor. The efficient defect healing has been confirmed also by low-temperature photoluminescence measurements by monitoring the attenuation of defect-related bands after Hg2+ exposure. Transfer characteristics in MoS2 FETs provided further evidence that Hg2+ acts as a p-dopant of MoS2. Interestingly, we observed a strict correlation of doping with the concentration of Hg2+, following a semi-log trend. Hg2+ concentrations as low as 1 pM can be detected, being way below the limits imposed by health regulations. Electrical characterization also revealed that our sensor can be efficiently washed and used multiple times. Moreover, the developed devices displayed a markedly high selectivity for Hg2+ against other metal ions as ruled by soft/soft interaction among chemical systems with appropriate redox potentials, being a generally applicable approach to develop chemical sensing devices combining high sensitivity, selectivity and reversibility, to meet technological needs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The contamination of water with heavy metal ions represents a harsh environmental problem resulting from societal development. Among various hazardous compounds, mercury ions (Hg2+) surely belong to the most poisonous ones. Their accumulation in the human body results in health deterioration, affecting vital organs and eventually leading to chronic diseases, and, in the worst-case scenario, early death. High selectivity and sensitivity for the analyte of choice can be achieved in chemical sensing using suitable active materials capable of interacting at the supramolecular level with the chosen species. Among them, 2D transition metal dichalcogenides (TMDCs) have attracted great attention as sensory materials because of their unique physical and chemical properties, which are highly susceptible to environmental changes. In this work, we have fabricated MoS2-based field-effect transistors (FETs) and exploited them as platforms for Hg2+ sensing, relying on the affinity of heavy metal ions for both point defects in TMDCs and sulphur atoms in the MoS2 lattice. X-ray photoelectron spectroscopy characterization showed both a significant reduction of the defectiveness of MoS2 when exposed to Hg2+ with increasing concentration and a shift in the binding energy of 0.2 eV suggesting p-type doping of the 2D semiconductor. The efficient defect healing has been confirmed also by low-temperature photoluminescence measurements by monitoring the attenuation of defect-related bands after Hg2+ exposure. Transfer characteristics in MoS2 FETs provided further evidence that Hg2+ acts as a p-dopant of MoS2. Interestingly, we observed a strict correlation of doping with the concentration of Hg2+, following a semi-log trend. Hg2+ concentrations as low as 1 pM can be detected, being way below the limits imposed by health regulations. Electrical characterization also revealed that our sensor can be efficiently washed and used multiple times. Moreover, the developed devices displayed a markedly high selectivity for Hg2+ against other metal ions as ruled by soft/soft interaction among chemical systems with appropriate redox potentials, being a generally applicable approach to develop chemical sensing devices combining high sensitivity, selectivity and reversibility, to meet technological needs. |
Liu, Z; Qiu, H; Fu, S; Wang, C; Yao, X; Dixon, A G; Campidelli, S; Pavlica, E; Bratina, G; Zhao, S; Rondin, L; Lauret, J -S; Narita, A; Bonn, M; Müllen, K; Ciesielski, A; H. I. Wang, ; Samorì, P Solution-Processed Graphene–Nanographene van der Waals Heterostructures for Photodetectors with Efficient and Ultralong Charge Separation Article de journal Dans: J. Am. Chem. Soc., 143 , p. 17109–17116, 2021. @article{Liu2021, title = {Solution-Processed Graphene–Nanographene van der Waals Heterostructures for Photodetectors with Efficient and Ultralong Charge Separation}, author = {Z. Liu and H. Qiu and S. Fu and C. Wang and X. Yao and A. G. Dixon and S. Campidelli and E. Pavlica and G. Bratina and S. Zhao and L. Rondin and J.-S. Lauret and A. Narita and M. Bonn and K. Müllen and A. Ciesielski and H. I. Wang, and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/jacs.1c07615}, year = {2021}, date = {2021-10-07}, journal = {J. Am. Chem. Soc.}, volume = {143}, pages = {17109–17116}, abstract = {Sensitization of graphene with inorganic semiconducting nanostructures has been demonstrated as a powerful strategy to boost its optoelectronic performance. However, the limited tunability of optical properties and toxicity of metal cations in the inorganic sensitizers prohibits their widespread applications, and the in-depth understanding of the essential interfacial charge-transfer process within such hybrid systems remains elusive. Here, we design and develop high-quality nanographene (NG) dispersions with a large-scale production using high-shear mixing exfoliation. The physisorption of these NG molecules onto graphene gives rise to the formation of graphene–NG van der Waals heterostructures (VDWHs), characterized by strong interlayer coupling through π–π interactions. As a proof of concept, photodetectors fabricated on the basis of such VDWHs show ultrahigh responsivity up to 4.5 × 107 A/W and a specific detectivity reaching 4.6 × 1013 Jones, being competitive with the highest values obtained for graphene-based photodetectors. The outstanding device characteristics are attributed to the efficient transfer of photogenerated holes from NGs to graphene and the long-lived charge separation at graphene–NG interfaces (beyond 1 ns), as elucidated by ultrafast terahertz (THz) spectroscopy. These results demonstrate the great potential of such graphene–NG VDWHs as prototypical building blocks for high-performance, low-toxicity optoelectronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Sensitization of graphene with inorganic semiconducting nanostructures has been demonstrated as a powerful strategy to boost its optoelectronic performance. However, the limited tunability of optical properties and toxicity of metal cations in the inorganic sensitizers prohibits their widespread applications, and the in-depth understanding of the essential interfacial charge-transfer process within such hybrid systems remains elusive. Here, we design and develop high-quality nanographene (NG) dispersions with a large-scale production using high-shear mixing exfoliation. The physisorption of these NG molecules onto graphene gives rise to the formation of graphene–NG van der Waals heterostructures (VDWHs), characterized by strong interlayer coupling through π–π interactions. As a proof of concept, photodetectors fabricated on the basis of such VDWHs show ultrahigh responsivity up to 4.5 × 107 A/W and a specific detectivity reaching 4.6 × 1013 Jones, being competitive with the highest values obtained for graphene-based photodetectors. The outstanding device characteristics are attributed to the efficient transfer of photogenerated holes from NGs to graphene and the long-lived charge separation at graphene–NG interfaces (beyond 1 ns), as elucidated by ultrafast terahertz (THz) spectroscopy. These results demonstrate the great potential of such graphene–NG VDWHs as prototypical building blocks for high-performance, low-toxicity optoelectronics. |
Qiu, H; Herder, M; Hecht, S; Samorì, P Ternary-Responsive Field-Effect Transistors and Multilevel Memories Based on Asymmetrically Functionalized Janus Few-Layer WSe2 Article de journal Dans: Adv. Funct. Mater., 31 (2102721), 2021. @article{Qiu2021b, title = {Ternary-Responsive Field-Effect Transistors and Multilevel Memories Based on Asymmetrically Functionalized Janus Few-Layer WSe2}, author = {H. Qiu and M. Herder and S. Hecht and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adfm.202102721}, year = {2021}, date = {2021-09-02}, journal = {Adv. Funct. Mater.}, volume = {31}, number = {2102721}, abstract = {Hybrids composed of 2D transition metal dichalcogenides with stimuli-responsive molecules are prototypical components for the development of multifunctional field-effect transistors (FETs), whose output currents can be remotely controlled by external inputs. Herein, ternary-responsive FETs based on a few-layer WSe2 are realized by decorating the two opposite surfaces of the 2D semiconductor with different stimuli-responsive molecules in an asymmetric fashion: the bottom surface is interfaced with a photochromic diarylethene film and the top surface with a ferroelectric poly(vinylidene fluoride–trifluoroethylene) layer. This novel Janus ternary device architecture shows superior functional complexity compared with normal mono-stimuli-responsive FETs. The synergy between the two molecularly induced effects enables the devices to respond orthogonally to an electric field and light irradiation, with an enhanced output current modulation efficiency of 87%. The 9 ferroelectric and 84 photo-generated states ensure 756 current levels in a single device. The over 10 cycles of cyclic endurance and more than 1000 h of retention time confirm the reliability of each state, implementing the demand for high-density non-volatile memories, as well as enriching the diversification in “More than Moore” technologies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hybrids composed of 2D transition metal dichalcogenides with stimuli-responsive molecules are prototypical components for the development of multifunctional field-effect transistors (FETs), whose output currents can be remotely controlled by external inputs. Herein, ternary-responsive FETs based on a few-layer WSe2 are realized by decorating the two opposite surfaces of the 2D semiconductor with different stimuli-responsive molecules in an asymmetric fashion: the bottom surface is interfaced with a photochromic diarylethene film and the top surface with a ferroelectric poly(vinylidene fluoride–trifluoroethylene) layer. This novel Janus ternary device architecture shows superior functional complexity compared with normal mono-stimuli-responsive FETs. The synergy between the two molecularly induced effects enables the devices to respond orthogonally to an electric field and light irradiation, with an enhanced output current modulation efficiency of 87%. The 9 ferroelectric and 84 photo-generated states ensure 756 current levels in a single device. The over 10 cycles of cyclic endurance and more than 1000 h of retention time confirm the reliability of each state, implementing the demand for high-density non-volatile memories, as well as enriching the diversification in “More than Moore” technologies. |
Gullace, S; Montes-García, V; Martín, V; Larios, D; Consolaro, Girelli V; Obelleiro, F; Calogero, G; Casalini, S; Samorì, P Universal Fabrication of Highly Efficient Plasmonic Thin-Films for Label-Free SERS Detection Article de journal Dans: Small, 17 (2100755), 2021. @article{Gullace2021, title = {Universal Fabrication of Highly Efficient Plasmonic Thin-Films for Label-Free SERS Detection}, author = {S. Gullace and V. Montes-García and V. Martín and D. Larios and V. Girelli Consolaro and F. Obelleiro and G. Calogero and S. Casalini and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smll.202100755}, year = {2021}, date = {2021-08-19}, journal = {Small}, volume = {17}, number = {2100755}, abstract = {The development of novel, highly efficient, reliable, and robust surface enhanced Raman scattering (SERS) substrates containing a large number of hot spots with programmed size, geometry, and density is extremely interesting since it allows the sensing of numerous (bio-)chemical species. Herein, an extremely reliable, easy to fabricate, and label-free SERS sensing platform based on metal nanoparticles (NPs) thin-film is developed by the layer-by-layer growth mediated by polyelectrolytes. A systematic study of the effect of NP composition and size, as well as the number of deposition steps on the substrate's performance, is accomplished by monitoring the SERS enhancement of 1-naphtalenethiol (532 nm excitation). Distinct evidence of the key role played by the interlayer (poly(diallyldimethylammonium chloride) (PDDA) or PDDA-functionalized graphene oxide (GO@PDDA)) on the overall SERS efficiency of the plasmonic platforms is provided, revealing in the latter the formation of more uniform hot spots by regulating the interparticle distances to 5 ± 1 nm. The SERS platform efficiency is demonstrated via its high analytical enhancement factor (≈106) and the detection of a prototypical substance(tamoxifen), both in Milli-Q water and in a real matrix, viz. tap water, opening perspectives towards the use of plasmonic platforms for future high-performance sensing applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of novel, highly efficient, reliable, and robust surface enhanced Raman scattering (SERS) substrates containing a large number of hot spots with programmed size, geometry, and density is extremely interesting since it allows the sensing of numerous (bio-)chemical species. Herein, an extremely reliable, easy to fabricate, and label-free SERS sensing platform based on metal nanoparticles (NPs) thin-film is developed by the layer-by-layer growth mediated by polyelectrolytes. A systematic study of the effect of NP composition and size, as well as the number of deposition steps on the substrate's performance, is accomplished by monitoring the SERS enhancement of 1-naphtalenethiol (532 nm excitation). Distinct evidence of the key role played by the interlayer (poly(diallyldimethylammonium chloride) (PDDA) or PDDA-functionalized graphene oxide (GO@PDDA)) on the overall SERS efficiency of the plasmonic platforms is provided, revealing in the latter the formation of more uniform hot spots by regulating the interparticle distances to 5 ± 1 nm. The SERS platform efficiency is demonstrated via its high analytical enhancement factor (≈106) and the detection of a prototypical substance(tamoxifen), both in Milli-Q water and in a real matrix, viz. tap water, opening perspectives towards the use of plasmonic platforms for future high-performance sensing applications. |
de Oliveira, Furlan R; Montes-García, V; Ciesielski, A; Samorì, P Harnessing selectivity in chemical sensing via supramolecular interactions: from functionalization of nanomaterials to device applications Article de journal Dans: Mater. Horiz., 8 , p. 2685–2708, 2021. @article{deOliveira2021, title = {Harnessing selectivity in chemical sensing via supramolecular interactions: from functionalization of nanomaterials to device applications}, author = {R. Furlan de Oliveira and V. Montes-García and A. Ciesielski and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1mh01117k}, year = {2021}, date = {2021-08-16}, journal = {Mater. Horiz.}, volume = {8}, pages = {2685–2708}, abstract = {Chemical sensing is a strategic field of science and technology ultimately aiming at improving the quality of our lives and the sustainability of our Planet. Sensors bear a direct societal impact on well-being, which includes the quality and composition of the air we breathe, the water we drink, and the food we eat. Pristine low-dimensional materials are widely exploited as highly sensitive elements in chemical sensors, although they suffer from lack of intrinsic selectivity towards specific analytes. Here, we showcase the most recent strategies on the use of (supra)molecular interactions to harness the selectivity of suitably functionalized 0D, 1D, and 2D low-dimensional materials for chemical sensing. We discuss how the design and selection of receptors via machine learning and artificial intelligence hold a disruptive potential in chemical sensing, where selectivity is achieved by the design and high-throughput screening of large libraries of molecules exhibiting a set of affinity parameters that dictates the analyte specificity. We also discuss the importance of achieving selectivity along with other relevant characteristics in chemical sensing, such as high sensitivity, response speed, and reversibility, as milestones for true practical applications. Finally, for each distinct class of low-dimensional material, we present the most suitable functionalization strategies for their incorporation into efficient transducers for chemical sensing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Chemical sensing is a strategic field of science and technology ultimately aiming at improving the quality of our lives and the sustainability of our Planet. Sensors bear a direct societal impact on well-being, which includes the quality and composition of the air we breathe, the water we drink, and the food we eat. Pristine low-dimensional materials are widely exploited as highly sensitive elements in chemical sensors, although they suffer from lack of intrinsic selectivity towards specific analytes. Here, we showcase the most recent strategies on the use of (supra)molecular interactions to harness the selectivity of suitably functionalized 0D, 1D, and 2D low-dimensional materials for chemical sensing. We discuss how the design and selection of receptors via machine learning and artificial intelligence hold a disruptive potential in chemical sensing, where selectivity is achieved by the design and high-throughput screening of large libraries of molecules exhibiting a set of affinity parameters that dictates the analyte specificity. We also discuss the importance of achieving selectivity along with other relevant characteristics in chemical sensing, such as high sensitivity, response speed, and reversibility, as milestones for true practical applications. Finally, for each distinct class of low-dimensional material, we present the most suitable functionalization strategies for their incorporation into efficient transducers for chemical sensing. |
Wang, Y; Iglesias, D; Gali, S M; Beljonne, D; Samorì, P Light-Programmable Logic-in-Memory in 2D Semiconductors Enabled by Supramolecular Functionalization: Photoresponsive Collective Effect of Aligned Molecular Dipoles Article de journal Dans: ACS Nano, 15 , p. 13732–13741, 2021. @article{Wang2021b, title = {Light-Programmable Logic-in-Memory in 2D Semiconductors Enabled by Supramolecular Functionalization: Photoresponsive Collective Effect of Aligned Molecular Dipoles}, author = {Y. Wang and D. Iglesias and S. M. Gali and D. Beljonne and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsnano.1c05167}, year = {2021}, date = {2021-08-09}, journal = {ACS Nano}, volume = {15}, pages = {13732–13741}, abstract = {Nowadays, the unrelenting growth of the digital universe calls for radically novel strategies for data processing and storage. An extremely promising and powerful approach relies on the development of logic-in-memory (LiM) devices through the use of floating gate and ferroelectric technologies to write and erase data in a memory operating as a logic gate driven by electrical bias. In this work, we report an alternative approach to realize the logic-in-memory based on two-dimensional (2D) transition metal dichalcogenides (TMDs) where multiple memorized logic output states have been established via the interface with responsive molecular dipoles arranged in supramolecular arrays. The collective dynamic molecular dipole changes of the axial ligand coordinated onto self-assembled metal phthalocyanine nanostructures on the surface of 2D TMD enables large reversible modulation of the Fermi level of both n-type molybdenum disulfide (MoS2) and p-type tungsten diselenide (WSe2) field-effect transistors (FETs), to achieve multiple memory states by programming and erasing with ultraviolet (UV) and with visible light, respectively. As a result, logic-in-memory devices were built up with our supramolecular layer/2D TMD architecture where the output logic is encoded by the motion of the molecular dipoles. Our strategy relying on the dynamic control of the 2D electronics by harnessing the functions of molecular-dipole-induced memory in a supramolecular hybrid layer represents a versatile way to integrate the functional programmability of molecular science into the next generation nanoelectronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Nowadays, the unrelenting growth of the digital universe calls for radically novel strategies for data processing and storage. An extremely promising and powerful approach relies on the development of logic-in-memory (LiM) devices through the use of floating gate and ferroelectric technologies to write and erase data in a memory operating as a logic gate driven by electrical bias. In this work, we report an alternative approach to realize the logic-in-memory based on two-dimensional (2D) transition metal dichalcogenides (TMDs) where multiple memorized logic output states have been established via the interface with responsive molecular dipoles arranged in supramolecular arrays. The collective dynamic molecular dipole changes of the axial ligand coordinated onto self-assembled metal phthalocyanine nanostructures on the surface of 2D TMD enables large reversible modulation of the Fermi level of both n-type molybdenum disulfide (MoS2) and p-type tungsten diselenide (WSe2) field-effect transistors (FETs), to achieve multiple memory states by programming and erasing with ultraviolet (UV) and with visible light, respectively. As a result, logic-in-memory devices were built up with our supramolecular layer/2D TMD architecture where the output logic is encoded by the motion of the molecular dipoles. Our strategy relying on the dynamic control of the 2D electronics by harnessing the functions of molecular-dipole-induced memory in a supramolecular hybrid layer represents a versatile way to integrate the functional programmability of molecular science into the next generation nanoelectronics. |
Chen, Y; Wang, H; Yao, Y; Wang, Y; Ma, C; Samorì, P Synaptic Plasticity Powering Long-Afterglow Organic Light-Emitting Transistors Article de journal Dans: Adv. Mater., 33 (2103369), 2021. @article{Chen2021, title = {Synaptic Plasticity Powering Long-Afterglow Organic Light-Emitting Transistors}, author = {Y. Chen and H. Wang and Y. Yao and Y. Wang and C. Ma and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adma.202103369}, year = {2021}, date = {2021-08-08}, journal = {Adv. Mater.}, volume = {33}, number = {2103369}, abstract = {Long-lasting luminescence in optoelectronic devices is highly sought after for applications in optical data storage and display technology. While in light-emitting diodes this is achieved by exploiting long-afterglow organic materials as active components, such a strategy has never been pursued in light-emitting transistors, which are still rather unexplored and whose technological potential is yet to be demonstrated. Herein, the fabrication of long-afterglow organic light-emitting transistors (LAOLETs) is reported whose operation relies on an unprecedented strategy based on a photoinduced synaptic effect in an inorganic indium-gallium-zinc-oxide (IGZO) semiconducting channel layer, to power a persistent electroluminescence in organic light-emitting materials. Oxygen vacancies in the IGZO layer, produced by irradiation at λ = 312 nm, free electrons in excess yielding to a channel conductance increase. Due to the slow recombination kinetics of photogenerated electrons to oxygen vacancies in the channel layer, the organic material can be fueled by postsynaptic current and displays a long-lived light-emission (hundreds of seconds) after ceasing UV irradiation. As a proof-of-concept, the LAOLETs are integrated in active-matrix light-emitting arrays operating as visual UV sensors capable of long-lifetime green-light emission in the irradiated regions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Long-lasting luminescence in optoelectronic devices is highly sought after for applications in optical data storage and display technology. While in light-emitting diodes this is achieved by exploiting long-afterglow organic materials as active components, such a strategy has never been pursued in light-emitting transistors, which are still rather unexplored and whose technological potential is yet to be demonstrated. Herein, the fabrication of long-afterglow organic light-emitting transistors (LAOLETs) is reported whose operation relies on an unprecedented strategy based on a photoinduced synaptic effect in an inorganic indium-gallium-zinc-oxide (IGZO) semiconducting channel layer, to power a persistent electroluminescence in organic light-emitting materials. Oxygen vacancies in the IGZO layer, produced by irradiation at λ = 312 nm, free electrons in excess yielding to a channel conductance increase. Due to the slow recombination kinetics of photogenerated electrons to oxygen vacancies in the channel layer, the organic material can be fueled by postsynaptic current and displays a long-lived light-emission (hundreds of seconds) after ceasing UV irradiation. As a proof-of-concept, the LAOLETs are integrated in active-matrix light-emitting arrays operating as visual UV sensors capable of long-lifetime green-light emission in the irradiated regions. |
Wang, Y; Wang, H; Gali, S M; Turetta, N; Yao, Y; Wang, C; anf Beljonne, Chen Y D; Samorì, P Molecular Doping of 2D Indium Selenide for Ultrahigh Performance and Low-Power Consumption Broadband Photodetectors Article de journal Dans: Adv. Funct. Mater., 31 (2103353), 2021. @article{Wang2021b, title = {Molecular Doping of 2D Indium Selenide for Ultrahigh Performance and Low-Power Consumption Broadband Photodetectors}, author = {Y. Wang and H. Wang and S. M. Gali and N. Turetta and Y. Yao and C. Wang and Y. Chen anf D. Beljonne and P. Samorì}, editor = {Wiley Online Library }, url = {https://doi.org/10.1002/adfm.202103353}, year = {2021}, date = {2021-07-23}, journal = {Adv. Funct. Mater.}, volume = {31}, number = {2103353}, abstract = {Two-dimensional (2D) photodetecting materials have shown superior performances over traditional materials (e.g., silicon, perylenes), which demonstrate low responsivity (R) (<1 AW−1), external quantum efficiency (EQE) (<100%), and limited detection bandwidth. Recently, 2D indium selenide (InSe) emerged as high-performance active material in field-effect transistors and photodetectors, whose fabrication required expensive and complex techniques. Here, it is shown for the first time how molecular functionalization with a common surfactant molecule (didodecyldimethylammonium bromide) (DDAB) represents a powerful strategy to boost the (opto)electronic performances of InSe yielding major performance enhancements in phototransistors, Schottky junctions, and van der Waals heterostructures via a lithography-compatible fabrication route. The functionalization can controllably dope and heal vacancies in InSe, resulting in ultrahigh field-effect mobility (103 cm2 V−1 s−1) and photoresponsivity (106 A W−1), breaking the record of non-graphene-contacted 2D photodetectors. The strategy towards the molecular doping of 2D photodetecting materials is efficient, practical, up-scalable, and operable with ultra-low power input, ultimately paving the way to next-generation 2D opto-electronics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Two-dimensional (2D) photodetecting materials have shown superior performances over traditional materials (e.g., silicon, perylenes), which demonstrate low responsivity (R) (<1 AW−1), external quantum efficiency (EQE) (<100%), and limited detection bandwidth. Recently, 2D indium selenide (InSe) emerged as high-performance active material in field-effect transistors and photodetectors, whose fabrication required expensive and complex techniques. Here, it is shown for the first time how molecular functionalization with a common surfactant molecule (didodecyldimethylammonium bromide) (DDAB) represents a powerful strategy to boost the (opto)electronic performances of InSe yielding major performance enhancements in phototransistors, Schottky junctions, and van der Waals heterostructures via a lithography-compatible fabrication route. The functionalization can controllably dope and heal vacancies in InSe, resulting in ultrahigh field-effect mobility (103 cm2 V−1 s−1) and photoresponsivity (106 A W−1), breaking the record of non-graphene-contacted 2D photodetectors. The strategy towards the molecular doping of 2D photodetecting materials is efficient, practical, up-scalable, and operable with ultra-low power input, ultimately paving the way to next-generation 2D opto-electronics. |
Anichini, C; Czepa, W; Aliprandi, A; Consolaro, Girelli V; Ersen, O; Ciesielski, A; Samorì, P Synthesis and characterization of ultralong copper sulfide nanowires and their electrical properties Article de journal Dans: J. Mater. Chem. C, 9 , p. 12133–12140, 2021. @article{Anichini2021b, title = {Synthesis and characterization of ultralong copper sulfide nanowires and their electrical properties}, author = {C. Anichini and W. Czepa and A. Aliprandi and V. Girelli Consolaro and O. Ersen and A. Ciesielski and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1tc03004c}, year = {2021}, date = {2021-07-21}, journal = {J. Mater. Chem. C}, volume = {9}, pages = {12133–12140}, abstract = { We report the synthesis of ultralong copper sulfide nanowires (Cu2−xSNWs) through the sulphidation reaction of metallic copper nanowires (CuNWs) by thiourea under mild conditions. The multiscale characterization of Cu2−xSNWs revealed the presence of a core shell structure made up of an external covellite layer coating a roxbyite core. The Cu2−xSNWs, exhibiting lengths as high as 200 μm, can be easily dispersed in ethanol and deposited onto arbitrary substrates such as glass or plastic. The resulting films are readily conducting without the need for post-treatments and exhibit a sheet resistance of 4.1 kΩ sq−1 at 73.7% transmittance (at 550 nm), by virtue of the high aspect ratio of the Cu2−xSNWs. The multiscale electrical characterization down to the single Cu2−xSNWs revealed a low resistivity of 6.9 × 10−6 Ω m and perfect Ohmic conductivity. Interestingly, the conductivity of Cu2−xSNW films supported on polyethylene naphthalate sheets remained almost unaltered (4% decrease) after 10 000 bending cycles. In addition, Cu2−xSNWs have shown excellent chemical stability towards a strong oxidant like FeCl3 as well as in an acidic environment. Finally, Cu2−xSNWs have been employed as active materials in symmetric supercapacitors revealing good pseudocapacitive behaviour, with specific capacity as high as 324 F g−1 (at 5 mV s−1) and 70% retention of the initial capacitance after 5000 cycles (at 100 mV s−1). }, keywords = {}, pubstate = {published}, tppubtype = {article} } We report the synthesis of ultralong copper sulfide nanowires (Cu2−xSNWs) through the sulphidation reaction of metallic copper nanowires (CuNWs) by thiourea under mild conditions. The multiscale characterization of Cu2−xSNWs revealed the presence of a core shell structure made up of an external covellite layer coating a roxbyite core. The Cu2−xSNWs, exhibiting lengths as high as 200 μm, can be easily dispersed in ethanol and deposited onto arbitrary substrates such as glass or plastic. The resulting films are readily conducting without the need for post-treatments and exhibit a sheet resistance of 4.1 kΩ sq−1 at 73.7% transmittance (at 550 nm), by virtue of the high aspect ratio of the Cu2−xSNWs. The multiscale electrical characterization down to the single Cu2−xSNWs revealed a low resistivity of 6.9 × 10−6 Ω m and perfect Ohmic conductivity. Interestingly, the conductivity of Cu2−xSNW films supported on polyethylene naphthalate sheets remained almost unaltered (4% decrease) after 10 000 bending cycles. In addition, Cu2−xSNWs have shown excellent chemical stability towards a strong oxidant like FeCl3 as well as in an acidic environment. Finally, Cu2−xSNWs have been employed as active materials in symmetric supercapacitors revealing good pseudocapacitive behaviour, with specific capacity as high as 324 F g−1 (at 5 mV s−1) and 70% retention of the initial capacitance after 5000 cycles (at 100 mV s−1). |
Campitiello, M; Cremonini, A; Squillaci, M A; Pieraccini, S; Ciesielski, A; Samorì, P; Masiero, S Self-Assembly of Functionalized Lipophilic Guanosines into Cation-Free Stacked Guanine-Quartets Article de journal Dans: J. Org. Chem., 86 , p. 9970–9978, 2021. @article{Campitiello2021, title = {Self-Assembly of Functionalized Lipophilic Guanosines into Cation-Free Stacked Guanine-Quartets}, author = {M. Campitiello and A. Cremonini and M. A. Squillaci and S. Pieraccini and A. Ciesielski and P. Samorì and S. Masiero}, editor = {ACS }, url = {https://doi.org/10.1021/acs.joc.1c00502}, year = {2021}, date = {2021-07-19}, journal = {J. Org. Chem.}, volume = {86}, pages = {9970–9978}, abstract = {The hierarchical self-assembly of various lipophilic guanosines exposing either a phenyl or a ferrocenyl group in the C(8) position was investigated. In a solution, all the derivatives were found to self-assemble primarily into isolated guanine (G)-quartets. In spite of the apparent similar bulkiness of the two substituents, most of the derivatives form disordered structures in the solid state, whereas a specific 8-phenyl derivative self-assembles into an unprecedented, cation-free stacked G-quartet architecture.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The hierarchical self-assembly of various lipophilic guanosines exposing either a phenyl or a ferrocenyl group in the C(8) position was investigated. In a solution, all the derivatives were found to self-assemble primarily into isolated guanine (G)-quartets. In spite of the apparent similar bulkiness of the two substituents, most of the derivatives form disordered structures in the solid state, whereas a specific 8-phenyl derivative self-assembles into an unprecedented, cation-free stacked G-quartet architecture. |
Krystek, M; Ciesielski, A; Samorì, P Graphene‐Based Cementitious Composites: Toward Next‐Generation Construction Technologies Article de journal Dans: Adv. Funct. Mater., 31 (2101887), 2021. @article{Krystek2021b, title = {Graphene‐Based Cementitious Composites: Toward Next‐Generation Construction Technologies}, author = {M. Krystek and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adfm.202101887}, year = {2021}, date = {2021-07-02}, journal = {Adv. Funct. Mater.}, volume = {31}, number = {2101887}, abstract = {The search for technological solutions to the ever-increasing demand for ultra-high-quality concrete with the simultaneous construction boom represents one of the greatest challenges concrete researchers are facing nowadays. In view of their unique properties, graphene and related materials, when utilized to form graphene-based cementitious composites, appear to be powerful components to give a boost to today's concrete technology. In this review, the most enlightening recent advancements in the development of fabrication protocols for obtaining the homogenous dispersion of graphene and derivatives thereof within the cement matrix are showcased. The hydration process and basic properties of graphene-based cementitious materials are also discussed. The integration of graphene-family materials to concrete technology allows new functions to be imparted to cement composites toward the construction of smart and multifunctional buildings. Therefore, a specific focus is given to the electrical and piezoresistive behavior of graphene-cement composites, and ultimately their great potential for structural health monitoring applications. The approaches proposed in this review can be also extended to other 2D materials offering the broadest arsenal of physical properties, which can therefore be integrated on-demand in future smart structures and constructions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The search for technological solutions to the ever-increasing demand for ultra-high-quality concrete with the simultaneous construction boom represents one of the greatest challenges concrete researchers are facing nowadays. In view of their unique properties, graphene and related materials, when utilized to form graphene-based cementitious composites, appear to be powerful components to give a boost to today's concrete technology. In this review, the most enlightening recent advancements in the development of fabrication protocols for obtaining the homogenous dispersion of graphene and derivatives thereof within the cement matrix are showcased. The hydration process and basic properties of graphene-based cementitious materials are also discussed. The integration of graphene-family materials to concrete technology allows new functions to be imparted to cement composites toward the construction of smart and multifunctional buildings. Therefore, a specific focus is given to the electrical and piezoresistive behavior of graphene-cement composites, and ultimately their great potential for structural health monitoring applications. The approaches proposed in this review can be also extended to other 2D materials offering the broadest arsenal of physical properties, which can therefore be integrated on-demand in future smart structures and constructions. |
Anichini, C; Samorì, P Graphene-Based Hybrid Functional Materials Article de journal Dans: Small, 17 (2100514), 2021. @article{Anichini2021, title = {Graphene-Based Hybrid Functional Materials}, author = {C. Anichini and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smll.202100514}, year = {2021}, date = {2021-06-26}, journal = {Small}, volume = {17}, number = {2100514}, abstract = {Graphene is a 2D material combining numerous outstanding physical properties, including high flexibility and strength, extremely high thermal conductivity and electron mobility, transparency, etc., which make it a unique testbed to explore fundamental physical phenomena. Such physical properties can be further tuned by combining graphene with other nanomaterials or (macro)molecules to form hybrid functional materials, which by design can display not only the properties of the individual components but also exhibit new properties and enhanced characteristics arising from the synergic interaction of the components. The implementation of the hybrid approach to graphene also allows boosting the performances in a multitude of technological applications. This review reports the hybrids formed by graphene combined with other low-dimensional nanomaterials of diverse dimensionality (0D, 1D, and 2D) and (macro)molecules, with emphasis on the synthetic methods. The most important applications of these hybrids in the fields of sensing, water purification, energy storage, biomedical, (photo)catalysis, and opto(electronics) are also reviewed, with a special focus on the superior performances of these hybrids compared to the individual, nonhybridized components.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Graphene is a 2D material combining numerous outstanding physical properties, including high flexibility and strength, extremely high thermal conductivity and electron mobility, transparency, etc., which make it a unique testbed to explore fundamental physical phenomena. Such physical properties can be further tuned by combining graphene with other nanomaterials or (macro)molecules to form hybrid functional materials, which by design can display not only the properties of the individual components but also exhibit new properties and enhanced characteristics arising from the synergic interaction of the components. The implementation of the hybrid approach to graphene also allows boosting the performances in a multitude of technological applications. This review reports the hybrids formed by graphene combined with other low-dimensional nanomaterials of diverse dimensionality (0D, 1D, and 2D) and (macro)molecules, with emphasis on the synthetic methods. The most important applications of these hybrids in the fields of sensing, water purification, energy storage, biomedical, (photo)catalysis, and opto(electronics) are also reviewed, with a special focus on the superior performances of these hybrids compared to the individual, nonhybridized components. |
Yao, Y; Ou, Q; Wang, K; Peng, H; Fang, F; Shi, Y; Wang, Y; Asperilla, Iglesias D; Shuai, Z; and S. Lara Avila, Samorì P Supramolecular engineering of charge transfer in wide bandgap organic semiconductors with enhanced visible-to-NIR photoresponse Article de journal Dans: Nat. Commun, 12 (3667), 2021. @article{Yao2021, title = {Supramolecular engineering of charge transfer in wide bandgap organic semiconductors with enhanced visible-to-NIR photoresponse}, author = {Y. Yao and Q. Ou and K. Wang and H. Peng and F. Fang and Y. Shi and Y. Wang and D. Iglesias Asperilla and Z. Shuai and S. Lara Avila ,and P. Samorì}, editor = {Nature communication}, url = {https://www.nature.com/articles/s41467-021-23914-2}, year = {2021}, date = {2021-06-16}, journal = {Nat. Commun}, volume = {12}, number = {3667}, abstract = {Organic photodetectors displaying efficient photoelectric response in the near-infrared are typically based on narrow bandgap active materials. Unfortunately, the latter require complex molecular design to ensure sufficient light absorption in the near-infrared region. Here, we show a method combining an unconventional device architecture and ad-hoc supramolecular self-assembly to trigger the emergence of opto-electronic properties yielding to remarkably high near-infrared response using a wide bandgap material as active component. Our optimized vertical phototransistors comprising a network of supramolecular nanowires of N,N′-dioctyl-3,4,9,10-perylenedicarboximide sandwiched between a monolayer graphene bottom-contact and Au nanomesh scaffold top-electrode exhibit ultrasensitive light response to monochromatic light from visible to near-infrared range, with photoresponsivity of 2 × 105 A/W and 1 × 102 A/W, at 570 nm and 940 nm, respectively, hence outperforming devices based on narrow bandgap materials. Moreover, these devices also operate as highly sensitive photoplethysmography tool for health monitoring.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organic photodetectors displaying efficient photoelectric response in the near-infrared are typically based on narrow bandgap active materials. Unfortunately, the latter require complex molecular design to ensure sufficient light absorption in the near-infrared region. Here, we show a method combining an unconventional device architecture and ad-hoc supramolecular self-assembly to trigger the emergence of opto-electronic properties yielding to remarkably high near-infrared response using a wide bandgap material as active component. Our optimized vertical phototransistors comprising a network of supramolecular nanowires of N,N′-dioctyl-3,4,9,10-perylenedicarboximide sandwiched between a monolayer graphene bottom-contact and Au nanomesh scaffold top-electrode exhibit ultrasensitive light response to monochromatic light from visible to near-infrared range, with photoresponsivity of 2 × 105 A/W and 1 × 102 A/W, at 570 nm and 940 nm, respectively, hence outperforming devices based on narrow bandgap materials. Moreover, these devices also operate as highly sensitive photoplethysmography tool for health monitoring. |
Cusin, L; Peng, H; Ciesielski, A; Samorì, P Chemical Conversion and Locking of the Imine Linkage: Enhancing the Functionality of Covalent Organic Frameworks Article de journal Dans: Angew. Chem. Int. Ed., 60 , p. 14236–14250, 2021. @article{Cusin2021, title = {Chemical Conversion and Locking of the Imine Linkage: Enhancing the Functionality of Covalent Organic Frameworks}, author = {L. Cusin and H. Peng and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/anie.202016667}, year = {2021}, date = {2021-06-16}, journal = {Angew. Chem. Int. Ed.}, volume = {60}, pages = {14236–14250}, abstract = {Imine-based covalent organic frameworks (COFs) are a widely studied class of functional, crystalline, and porous nanostructures which combine a relatively facile crystallization with tuneable compositions and porosities. However, the imine linkage constitutes an intrinsic limitation due to its reduced stability in harsh chemical conditions and its unsuitability for in-plane π-conjugation in COFs. Urgent solutions are therefore required in order to exploit the full potential of these materials, thereby enabling their technological application in electronics, sensing, and energy storage devices. In this context, the advent of a new generation of linkages derived from the chemical conversion and locking of the imine bond represents a cornerstone for the synthesis of new COFs. A marked increase in the framework robustness is in fact often combined with the incorporation of novel functionalities including, for some of these reactions, an extension of the in-plane π-conjugation. This Minireview describes the most enlightening examples of one-pot reactions and post-synthetic modifications towards the chemical locking of the imine bond in COFs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Imine-based covalent organic frameworks (COFs) are a widely studied class of functional, crystalline, and porous nanostructures which combine a relatively facile crystallization with tuneable compositions and porosities. However, the imine linkage constitutes an intrinsic limitation due to its reduced stability in harsh chemical conditions and its unsuitability for in-plane π-conjugation in COFs. Urgent solutions are therefore required in order to exploit the full potential of these materials, thereby enabling their technological application in electronics, sensing, and energy storage devices. In this context, the advent of a new generation of linkages derived from the chemical conversion and locking of the imine bond represents a cornerstone for the synthesis of new COFs. A marked increase in the framework robustness is in fact often combined with the incorporation of novel functionalities including, for some of these reactions, an extension of the in-plane π-conjugation. This Minireview describes the most enlightening examples of one-pot reactions and post-synthetic modifications towards the chemical locking of the imine bond in COFs. |
Qiu, H; Ippolito, S; Galanti, A; Liu, Z; Samorì, P Asymmetric Dressing of WSe2 with (Macro)molecular Switches: Fabrication of Quaternary-Responsive Transistors Article de journal Dans: ACS Nano, 15 (10668–10677), 2021. @article{Qiu2021, title = {Asymmetric Dressing of WSe2 with (Macro)molecular Switches: Fabrication of Quaternary-Responsive Transistors}, author = {H. Qiu and S. Ippolito and A. Galanti and Z. Liu and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsnano.1c03549}, year = {2021}, date = {2021-06-07}, journal = {ACS Nano}, volume = {15}, number = {10668–10677}, abstract = {The forthcoming saturation of Moore’s law has led to a strong demand for integrating analogue functionalities within semiconductor-based devices. As a step toward this goal, we fabricate quaternary-responsive WSe2-based field-effect transistors (FETs) whose output current can be remotely and reversibly controlled by light, heat, and electric field. A photochromic silane-terminated spiropyran (SP) is chemisorbed on SiO2 forming a self-assembled monolayer (SAM) that can switch from the SP to the merocyanine (MC) form in response to UV illumination and switch back by either heat or visible illumination. Such a SAM is incorporated at the dielectric–semiconductor interface in WSe2-based FETs. Upon UV irradiation, a drastic decrease in the output current of 82% is observed and ascribed to the zwitterionic MC isomer acting as charge scattering site. To provide an additional functionality, the WSe2 top surface is coated with a ferroelectric co-polymer layer based on poly(vinylidene fluoride-co-trifluoroethylene). Because of its switchable inherent electrical polarization, it can promote either the accumulation or depletion of charge carriers in the WSe2 channel, thereby inducing a current modulation with 99% efficiency. Thanks to the efficient tuning induced by the two components and their synergistic effects, the device polarity could be modulated from n-type to p-type. Such a control over the carrier concentration and device polarity is key to develop 2D advanced electronics. Moreover, the integration strategy of multiple stimuli-responsive elements into a single FET allows us to greatly enrich its functionality, thereby promoting the development for More-than-Moore technology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The forthcoming saturation of Moore’s law has led to a strong demand for integrating analogue functionalities within semiconductor-based devices. As a step toward this goal, we fabricate quaternary-responsive WSe2-based field-effect transistors (FETs) whose output current can be remotely and reversibly controlled by light, heat, and electric field. A photochromic silane-terminated spiropyran (SP) is chemisorbed on SiO2 forming a self-assembled monolayer (SAM) that can switch from the SP to the merocyanine (MC) form in response to UV illumination and switch back by either heat or visible illumination. Such a SAM is incorporated at the dielectric–semiconductor interface in WSe2-based FETs. Upon UV irradiation, a drastic decrease in the output current of 82% is observed and ascribed to the zwitterionic MC isomer acting as charge scattering site. To provide an additional functionality, the WSe2 top surface is coated with a ferroelectric co-polymer layer based on poly(vinylidene fluoride-co-trifluoroethylene). Because of its switchable inherent electrical polarization, it can promote either the accumulation or depletion of charge carriers in the WSe2 channel, thereby inducing a current modulation with 99% efficiency. Thanks to the efficient tuning induced by the two components and their synergistic effects, the device polarity could be modulated from n-type to p-type. Such a control over the carrier concentration and device polarity is key to develop 2D advanced electronics. Moreover, the integration strategy of multiple stimuli-responsive elements into a single FET allows us to greatly enrich its functionality, thereby promoting the development for More-than-Moore technology. |
Jiang, B; Che, Y; Chen, Y; Zhao, Y; Wang, C; Li, W; Zheng, H; Huang, X; Samorì, P; Zhang, L Wafer-Scale and Full-Coverage Two-Dimensional Molecular Monolayers Strained by Solvent Surface Tension Balance Article de journal Dans: ACS Appl. Mater. Interfaces, 13 , p. 26218–26226, 2021. @article{Jiang2021, title = {Wafer-Scale and Full-Coverage Two-Dimensional Molecular Monolayers Strained by Solvent Surface Tension Balance}, author = {B. Jiang and Y. Che and Y. Chen and Y. Zhao and C. Wang and W. Li and H. Zheng and X. Huang and P. Samorì and L. Zhang}, editor = {ACS }, url = {https://doi.org/10.1021/acsami.1c04198}, year = {2021}, date = {2021-05-31}, journal = {ACS Appl. Mater. Interfaces}, volume = {13}, pages = {26218–26226}, abstract = {Inspired by the outstanding properties discovered in two-dimensional materials, the bottom-up generation of molecular monolayers is becoming again extremely popular as a route to develop novel functional materials and devices with tailored characteristics and minimal materials consumption. However, achieving a full-coverage over a large-area still represents a grand challenge. Here we report a molecular self-assembly protocol at the water surface in which the monolayers are strained by a novel solvent surface tension balance (SSTB) instead of a physical film balance as in the conventional Langmuir–Blodgett (LB) method. The obtained molecular monolayers can be transferred onto any arbitrary substrate including rigid inorganic oxides and metals, as well as flexible polymeric dielectrics. As a proof-of-concept, their application as ideal modification layers of a dielectric support for high-performance organic field-effect transistors (OFETs) has been demonstrated. The field-effect mobilities of both p- and n-type semiconductors displayed dramatic improvements of 1–3 orders of magnitude on SSTB-derived molecular monolayer, reaching values as high as 6.16 cm2 V–1 s–1 and 0.68 cm2 V–1 s–1 for pentacene and PTCDI-C8, respectively. This methodology for the fabrication of wafer-scale and defect-free molecular monolayers holds potential toward the emergence of a new generation of high-performance electronics based on two-dimensional materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Inspired by the outstanding properties discovered in two-dimensional materials, the bottom-up generation of molecular monolayers is becoming again extremely popular as a route to develop novel functional materials and devices with tailored characteristics and minimal materials consumption. However, achieving a full-coverage over a large-area still represents a grand challenge. Here we report a molecular self-assembly protocol at the water surface in which the monolayers are strained by a novel solvent surface tension balance (SSTB) instead of a physical film balance as in the conventional Langmuir–Blodgett (LB) method. The obtained molecular monolayers can be transferred onto any arbitrary substrate including rigid inorganic oxides and metals, as well as flexible polymeric dielectrics. As a proof-of-concept, their application as ideal modification layers of a dielectric support for high-performance organic field-effect transistors (OFETs) has been demonstrated. The field-effect mobilities of both p- and n-type semiconductors displayed dramatic improvements of 1–3 orders of magnitude on SSTB-derived molecular monolayer, reaching values as high as 6.16 cm2 V–1 s–1 and 0.68 cm2 V–1 s–1 for pentacene and PTCDI-C8, respectively. This methodology for the fabrication of wafer-scale and defect-free molecular monolayers holds potential toward the emergence of a new generation of high-performance electronics based on two-dimensional materials. |
Turetta, N; Sedona, F; Liscio, A; Sambi, M; Samorì, P Au(111) Surface Contamination in Ambient Conditions: Unravelling the Dynamics of the Work Function in Air Article de journal Dans: Adv. Mater. Interfaces, 8 (2100068), 2021. @article{Sedona2021, title = {Au(111) Surface Contamination in Ambient Conditions: Unravelling the Dynamics of the Work Function in Air}, author = {N. Turetta And F. Sedona and A. Liscio and M. Sambi and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/admi.202100068}, year = {2021}, date = {2021-05-21}, journal = {Adv. Mater. Interfaces}, volume = {8}, number = {2100068}, abstract = {Gold is an inert noble metal displaying superior chemical stability that renders it a suitable component for the manufacturing of electrodes for various types of devices. Despite being widely employed, the variation of gold surface properties occurring upon the material's exposure to ambient conditions have been often disregarded. While it is well-known that the contamination of a metallic surface can have a dramatic impact on its properties, the process of contamination itself is poorly understood. Changes of the work function by fractions of an electron-volt are commonly observed in gold surfaces that are processed at ambient laboratory conditions, but an exhaustive comprehension and control of this phenomenon are still lacking. Here, a multiscale characterization of Au(111) surfaces aiming to unravel the surface dynamics underlying the air contamination is presented. The visualization of the adventitious carbon contamination on Au(111) surface by atomic force microscopy is key to rationalize the mechanisms of surface reorganization ruling the change of Au work function between 5.25 and 4.75 eV by solely changing the storage conditions. Such a huge variation must be taken into account when optimizing the Au surface for both controlling its fundamental surface and interfacial physical processes, as well as its functional applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Gold is an inert noble metal displaying superior chemical stability that renders it a suitable component for the manufacturing of electrodes for various types of devices. Despite being widely employed, the variation of gold surface properties occurring upon the material's exposure to ambient conditions have been often disregarded. While it is well-known that the contamination of a metallic surface can have a dramatic impact on its properties, the process of contamination itself is poorly understood. Changes of the work function by fractions of an electron-volt are commonly observed in gold surfaces that are processed at ambient laboratory conditions, but an exhaustive comprehension and control of this phenomenon are still lacking. Here, a multiscale characterization of Au(111) surfaces aiming to unravel the surface dynamics underlying the air contamination is presented. The visualization of the adventitious carbon contamination on Au(111) surface by atomic force microscopy is key to rationalize the mechanisms of surface reorganization ruling the change of Au work function between 5.25 and 4.75 eV by solely changing the storage conditions. Such a huge variation must be taken into account when optimizing the Au surface for both controlling its fundamental surface and interfacial physical processes, as well as its functional applications. |
Pakulski, D; Gorczyński, A; Marcinkowski, D; Czepa, W; Chudziak, T; Witomska, S; Nishina, Y; Patroniak, V; Ciesielski, A; Samorì, Paolo High-sorption terpyridine–graphene oxide hybrid for the efficient removal of heavy metal ions from wastewater Article de journal Dans: Nanoscale, 13 , p. 10490–10499, 2021. @article{Pakulski2021, title = {High-sorption terpyridine–graphene oxide hybrid for the efficient removal of heavy metal ions from wastewater}, author = {D. Pakulski and A. Gorczyński and D. Marcinkowski and W. Czepa and T. Chudziak and S. Witomska and Y. Nishina and V. Patroniak and A. Ciesielski and Paolo Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1nr02255e}, year = {2021}, date = {2021-05-12}, journal = {Nanoscale}, volume = {13}, pages = {10490–10499}, abstract = {Pollution of wastewater with heavy metal-ions represents one of the most severe environmental problems associated with societal development. To overcome this issue, the design of new, highly efficient systems capable of removing such toxic species, hence to purify water, is of paramount importance for public health and environmental protection. In this work, novel sorption hybrid materials were developed to enable high-performance adsorption of heavy metal ions. Towards this end, graphene oxide (GO) exhibiting various C/O ratios has been functionalized with ad hoc receptors, i.e. terpyridine ligands. The maximum adsorption capacity of highly oxidized/terpyridine hybrids towards Ni(II), Zn(II) and Co(II) was achieved at pH = 6 and 25 °C reaching values of 462, 421 and 336 mg g−1, respectively, being the highest reported in the literature for pristine GO and GO-based sorbents. Moreover, the uptake experiments showed that heavy metal ion adsorption on GO–Tpy and GOh–Tpy is strongly dependent on pH in the range from 2 to 10, as a result of the modulation of interactions at the supramolecular level. Moreover, the ionic strength was found to be independent of heavy metal ion adsorption on GO–Tpy and GOh–Tpy. Under ambient conditions, adsorption capacity values increase with the degree of oxidation of GO because dipolar oxygen units can both interact with heavy-metal ions via dipole–dipole and/or ionic interactions and enable bonding of more covalently anchored terpyridine units. Both adsorption isotherms and kinetics studies revealed that the uptake of the heavy metal ions occurs at a monolayer coverage, mostly controlled by the strong surface complexation with the oxygen of GO and nitrogen-containing groups of terpyridine. Furthermore, selectivity of the hybrid was confirmed by selective sorption of the above heavy metal ions from mixtures involving alkali (Na(I), K(I)) and alkaline Earth (Mg(II), Ca(II)) metal ions due to the chelating properties of the terpyridine subunits, as demonstrated with municipal drinking (tap) water samples. Our findings provide unambiguous evidence for the potential of chemical tailoring of GO-based materials with N-heterocyclic ligands as sorbent materials for highly efficient wastewater purification.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pollution of wastewater with heavy metal-ions represents one of the most severe environmental problems associated with societal development. To overcome this issue, the design of new, highly efficient systems capable of removing such toxic species, hence to purify water, is of paramount importance for public health and environmental protection. In this work, novel sorption hybrid materials were developed to enable high-performance adsorption of heavy metal ions. Towards this end, graphene oxide (GO) exhibiting various C/O ratios has been functionalized with ad hoc receptors, i.e. terpyridine ligands. The maximum adsorption capacity of highly oxidized/terpyridine hybrids towards Ni(II), Zn(II) and Co(II) was achieved at pH = 6 and 25 °C reaching values of 462, 421 and 336 mg g−1, respectively, being the highest reported in the literature for pristine GO and GO-based sorbents. Moreover, the uptake experiments showed that heavy metal ion adsorption on GO–Tpy and GOh–Tpy is strongly dependent on pH in the range from 2 to 10, as a result of the modulation of interactions at the supramolecular level. Moreover, the ionic strength was found to be independent of heavy metal ion adsorption on GO–Tpy and GOh–Tpy. Under ambient conditions, adsorption capacity values increase with the degree of oxidation of GO because dipolar oxygen units can both interact with heavy-metal ions via dipole–dipole and/or ionic interactions and enable bonding of more covalently anchored terpyridine units. Both adsorption isotherms and kinetics studies revealed that the uptake of the heavy metal ions occurs at a monolayer coverage, mostly controlled by the strong surface complexation with the oxygen of GO and nitrogen-containing groups of terpyridine. Furthermore, selectivity of the hybrid was confirmed by selective sorption of the above heavy metal ions from mixtures involving alkali (Na(I), K(I)) and alkaline Earth (Mg(II), Ca(II)) metal ions due to the chelating properties of the terpyridine subunits, as demonstrated with municipal drinking (tap) water samples. Our findings provide unambiguous evidence for the potential of chemical tailoring of GO-based materials with N-heterocyclic ligands as sorbent materials for highly efficient wastewater purification. |
Krystek, M; Pakulski, D; Górski, M; Szojda, L; Ciesielski, A; Samorì, P Electrochemically Exfoliated Graphene for High-Durability Cement Composites Article de journal Dans: ACS Appl. Mater. Interfaces, 13 , p. 23000–23010, 2021. @article{Krystek2021, title = {Electrochemically Exfoliated Graphene for High-Durability Cement Composites}, author = {M. Krystek and D. Pakulski and M. Górski and L. Szojda and A. Ciesielski and P. Samorì}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsami.1c04451}, year = {2021}, date = {2021-05-04}, journal = {ACS Appl. Mater. Interfaces}, volume = {13}, pages = {23000–23010}, abstract = {The development of radically new types of corrosion-resistant cement composites is nowadays compulsory in view of the continuous increase of concrete consumption combined with the intrinsically defective nature of concrete. Among various additives being employed in the concrete technology, carbon nanomaterials have emerged as extremely powerful components capable of remarkably enhancing nano- and microstructures as well as properties of cement-based composites. In this study, we demonstrate that cement mortar incorporating electrochemically exfoliated graphene (EEG) exhibits significantly improved fluid transport properties. The addition of 0.05 wt % of EEG to ordinary Portland cement mortar results in the reduction of initial and secondary sorptivity values by 21 and 25%, respectively. This leads to the outstanding resistance of EEG–cement composites to highly corrosive environments, namely, chloride and sulfate solutions. These observations, combined with the previously reported remarkable enhancement of the tensile strength of EEG–cement mortars, represent a major step toward the development of highly durable graphene-based cement composites.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The development of radically new types of corrosion-resistant cement composites is nowadays compulsory in view of the continuous increase of concrete consumption combined with the intrinsically defective nature of concrete. Among various additives being employed in the concrete technology, carbon nanomaterials have emerged as extremely powerful components capable of remarkably enhancing nano- and microstructures as well as properties of cement-based composites. In this study, we demonstrate that cement mortar incorporating electrochemically exfoliated graphene (EEG) exhibits significantly improved fluid transport properties. The addition of 0.05 wt % of EEG to ordinary Portland cement mortar results in the reduction of initial and secondary sorptivity values by 21 and 25%, respectively. This leads to the outstanding resistance of EEG–cement composites to highly corrosive environments, namely, chloride and sulfate solutions. These observations, combined with the previously reported remarkable enhancement of the tensile strength of EEG–cement mortars, represent a major step toward the development of highly durable graphene-based cement composites. |
Wang, H; Wang, Y; Ni, Z; Turetta, N; Gali, S M; Peng, H; Yao, Y; Chen, Y; Janica, I; Beljonne, D; Hu, W; Ciesielski, A; Samorì, P 2D MXene–Molecular Hybrid Additive for High-Performance Ambipolar Polymer Field-Effect Transistors and Logic Gates Article de journal Dans: Adv. Mater., 33 , p. 2008215, 2021. @article{Wang2021, title = {2D MXene–Molecular Hybrid Additive for High-Performance Ambipolar Polymer Field-Effect Transistors and Logic Gates}, author = {H. Wang and Y. Wang and Z. Ni and N. Turetta and S. M. Gali and H. Peng and Y. Yao and Y. Chen and I. Janica and D. Beljonne and W. Hu and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adma.202008215}, year = {2021}, date = {2021-04-12}, journal = {Adv. Mater.}, volume = {33}, pages = {2008215}, abstract = {MXenes are highly conductive layered materials that are attracting a great interest for high-performance opto-electronics, photonics, and energy applications.. Their non-covalent functionalization with ad hoc molecules enables the production of stable inks of 2D flakes to be processed in thin-films. Here, the formation of stable dispersions via the intercalation of Ti3C2Tx with didecyldimethyl ammonium bromide (DDAB) yielding Ti3C2Tx–DDAB, is demonstrated. Such functionalization modulates the properties of Ti3C2Tx, as evidenced by a 0.47 eV decrease of the work function. It is also shown that DDAB is a powerful n-dopant capable of enhancing electron mobility in conjugated polymers and 2D materials. When Ti3C2Tx–DDAB is blended with poly(diketopyrrolopyrrole-co-selenophene) [(PDPP–Se)], a simultaneous increase by 170% and 152% of the hole and electron field-effect mobilities, respectively, is observed, compared to the neat conjugated polymer, with values reaching 2.0 cm2 V−1 s−1. By exploiting the balanced ambipolar transport of the Ti3C2Tx–DDAB/PDPP–Se hybrid, complementary metal–oxide–semiconductor (CMOS) logic gates are fabricated that display well-centered trip points and good noise margin (64.6% for inverter). The results demonstrate that intercalant engineering represents an efficient strategy to tune the electronic properties of Ti3C2Tx yielding functionalized MXenes for polymer transistors with unprecedented performances and functions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } MXenes are highly conductive layered materials that are attracting a great interest for high-performance opto-electronics, photonics, and energy applications.. Their non-covalent functionalization with ad hoc molecules enables the production of stable inks of 2D flakes to be processed in thin-films. Here, the formation of stable dispersions via the intercalation of Ti3C2Tx with didecyldimethyl ammonium bromide (DDAB) yielding Ti3C2Tx–DDAB, is demonstrated. Such functionalization modulates the properties of Ti3C2Tx, as evidenced by a 0.47 eV decrease of the work function. It is also shown that DDAB is a powerful n-dopant capable of enhancing electron mobility in conjugated polymers and 2D materials. When Ti3C2Tx–DDAB is blended with poly(diketopyrrolopyrrole-co-selenophene) [(PDPP–Se)], a simultaneous increase by 170% and 152% of the hole and electron field-effect mobilities, respectively, is observed, compared to the neat conjugated polymer, with values reaching 2.0 cm2 V−1 s−1. By exploiting the balanced ambipolar transport of the Ti3C2Tx–DDAB/PDPP–Se hybrid, complementary metal–oxide–semiconductor (CMOS) logic gates are fabricated that display well-centered trip points and good noise margin (64.6% for inverter). The results demonstrate that intercalant engineering represents an efficient strategy to tune the electronic properties of Ti3C2Tx yielding functionalized MXenes for polymer transistors with unprecedented performances and functions. |
Carroli, M; Dixon, A G; Herder, M; Pavlica, E; Hecht, S; Bratina, G; Orgiu, E; Samorì, P Multiresponsive Nonvolatile Memories Based on Optically Switchable Ferroelectric Organic Field‐Effect Transistors Article de journal Dans: Adv. Mater., 33 (2007965), 2021. @article{Carroli2021, title = {Multiresponsive Nonvolatile Memories Based on Optically Switchable Ferroelectric Organic Field‐Effect Transistors}, author = {M. Carroli and A. G. Dixon and M. Herder and E. Pavlica and S. Hecht and G. Bratina and E. Orgiu and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adma.202007965}, year = {2021}, date = {2021-04-07}, journal = {Adv. Mater.}, volume = {33}, number = {2007965}, abstract = {Organic transistors are key elements for flexible, wearable, and biocompatible logic applications. Multiresponsivity is highly sought‐after in organic electronics to enable sophisticated operations and functions. Such a challenge can be pursued by integrating more components in a single device, each one responding to a specific external stimulus. Here, the first multiresponsive organic device based on a photochromic–ferroelectric organic field‐effect transistor, which is capable of operating as nonvolatile memory with 11 bit memory storage capacity in a single device, is reported. The memory elements can be written and erased independently by means of light or an electric field, with accurate control over the readout signal, excellent repeatability, fast response, and high retention time. Such a proof of concept paves the way toward enhanced functional complexity in optoelectronics via the interfacing of multiple components in a single device, in a fully integrated low‐cost technology compatible with flexible substrates.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Organic transistors are key elements for flexible, wearable, and biocompatible logic applications. Multiresponsivity is highly sought‐after in organic electronics to enable sophisticated operations and functions. Such a challenge can be pursued by integrating more components in a single device, each one responding to a specific external stimulus. Here, the first multiresponsive organic device based on a photochromic–ferroelectric organic field‐effect transistor, which is capable of operating as nonvolatile memory with 11 bit memory storage capacity in a single device, is reported. The memory elements can be written and erased independently by means of light or an electric field, with accurate control over the readout signal, excellent repeatability, fast response, and high retention time. Such a proof of concept paves the way toward enhanced functional complexity in optoelectronics via the interfacing of multiple components in a single device, in a fully integrated low‐cost technology compatible with flexible substrates. |
Stoeckel, M ‐A; Olivier, Y; Gobbi, M; Dudenko, D; Lemaur, V; Zbiri, M; Guilbert, A A Y; D'Avino, G; Liscio, F; Migliori, A; Ortolani, L; Demitri, N; Jin, X; Jeong, Y ‐G; Liscio, A; Nardia, M ‐V; Pasquali, L; Razzari, L; Beljonne, D; Samorì, P; Orgiu, E Analysis of External and Internal Disorder to Understand Band‐Like Transport in n‐Type Organic Semiconductors Article de journal Dans: Adv. Mater., 33 (2007870), 2021. @article{Stoeckel2021, title = {Analysis of External and Internal Disorder to Understand Band‐Like Transport in n‐Type Organic Semiconductors}, author = {M.‐A. Stoeckel and Y. Olivier and M. Gobbi and D. Dudenko and V. Lemaur and M. Zbiri and A. A. Y. Guilbert and G. D'Avino and F. Liscio and A. Migliori and L. Ortolani and N. Demitri and X. Jin and Y.‐G. Jeong and A. Liscio and M.‐V. Nardia and L. Pasquali and L. Razzari and D. Beljonne and P. Samorì and E. Orgiu}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adma.202007870}, year = {2021}, date = {2021-04-01}, journal = {Adv. Mater.}, volume = {33}, number = {2007870}, abstract = {Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both internal and external (i.e., related to interactions with the dielectric layer), especially for n‐type materials. Internal dynamic disorder stems from large thermal fluctuations both in intermolecular transfer integrals and (molecular) site energies in weakly interacting van der Waals solids and sources transient localization of the charge carriers. The molecular vibrations that drive transient localization typically operate at low‐frequency ( pubstate = {published}, tppubtype = {article} } Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both internal and external (i.e., related to interactions with the dielectric layer), especially for n‐type materials. Internal dynamic disorder stems from large thermal fluctuations both in intermolecular transfer integrals and (molecular) site energies in weakly interacting van der Waals solids and sources transient localization of the charge carriers. The molecular vibrations that drive transient localization typically operate at low‐frequency (<a‐few‐hundred cm−1), which makes it difficult to assess them experimentally. Hitherto, this has prevented the identification of clear molecular design rules to control and reduce dynamic disorder. In addition, the disorder can also be external, being controlled by the gate insulator dielectric properties. Here a comprehensive study of charge transport in two closely related n‐type molecular organic semiconductors using a combination of temperature‐dependent inelastic neutron scattering and photoelectron spectroscopy corroborated by electrical measurements, theory, and simulations is reported. Unambiguous evidence that ad hoc molecular design enables the electron charge carriers to be freed from both internal and external disorder to ultimately reach band‐like electron transport is provided. |
Backes, C; Behera, R K; Bianco, A; Casiraghi, C; Doan, H; Criado, A; Galembeck, F; Goldie, S; Gravagnuolo, A M; Hou, H -L; Kamali, A R; Kostarelos, K; Kumar, V; Lee, W H; Martsinovich, N; Palermo, V; Palma, M; Pang, J; Prato, M; Samorì, P; Silvestri, A; Singh, S; Strano, M; Wetzl, C Biomedical applications: general discussion Article de journal Dans: Faraday Discuss., 227 , p. 245–258, 2021. @article{Backes2021, title = {Biomedical applications: general discussion}, author = {C. Backes and R. K. Behera and A. Bianco and C. Casiraghi and H. Doan and A. Criado and F. Galembeck and S. Goldie and A. M. Gravagnuolo and H.-L. Hou and A. R. Kamali and K. Kostarelos and V. Kumar and W. H. Lee and N. Martsinovich and V. Palermo and M. Palma and J. Pang and M. Prato and P. Samorì and A. Silvestri and S. Singh and M. Strano and C. Wetzl}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1fd90003j}, year = {2021}, date = {2021-03-24}, journal = {Faraday Discuss.}, volume = {227}, pages = {245–258}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Backes, C; Bianco, A; Casiraghi, C; Galembeck, F; Gupta, R K; Hersam, M C; Kamali, A R; Kolíbal, M; Kolosov, V; Kumar, V; Lee, W H; Martsinovich, N; Melchionna, M; Müllen, K; Oyarzun, A; Palermo, V; Prato, M; Samorì, P; Sampath, S; Silvestri, A; Sirbu, D; Sui, R; Turchanin, A; Wetzl, C; Wright, I A; Xia, Z; Zhuang, X 2D materials production and generation of functional inks: general discussion Article de journal Dans: Faraday Discuss., 227 , p. 141-162, 2021. @article{Backes2021b, title = {2D materials production and generation of functional inks: general discussion}, author = {C. Backes and A. Bianco and C. Casiraghi and F. Galembeck and R. K. Gupta and M. C. Hersam and A. R. Kamali and M. Kolíbal and V. Kolosov and V. Kumar and W. H. Lee and N. Martsinovich and M. Melchionna and K. Müllen and A. Oyarzun and V. Palermo and M. Prato and P. Samorì and S. Sampath and A. Silvestri and D. Sirbu and R. Sui and A. Turchanin and C. Wetzl and I. A. Wright and Z. Xia and X. Zhuang}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d1fd90002a}, year = {2021}, date = {2021-03-24}, journal = {Faraday Discuss.}, volume = {227}, pages = {141-162}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Reina, G; Iglesias, D; Samorì, P; Bianco, A Graphene: A Disruptive Opportunity for COVID‐19 and Future Pandemics? Article de journal Dans: Adv. Mater., 33 (2007847), 2021. @article{Reina2021, title = {Graphene: A Disruptive Opportunity for COVID‐19 and Future Pandemics?}, author = {G. Reina and D. Iglesias and P. Samorì and A. Bianco}, editor = {Wiley Online Library }, url = {https://doi.org/10.1002/adma.202007847}, year = {2021}, date = {2021-03-11}, journal = {Adv. Mater.}, volume = {33}, number = {2007847}, abstract = {The graphene revolution, which has taken place during the last 15 years, has represented a paradigm shift for science. The extraordinary properties possessed by this unique material have paved the road to a number of applications in materials science, optoelectronics, energy, and sensing. Graphene‐related materials (GRMs) are now produced in large scale and have found niche applications also in the biomedical technologies, defining new standards for drug delivery and biosensing. Such advances position GRMs as novel tools to fight against the current COVID‐19 and future pandemics. In this regard, GRMs can play a major role in sensing, as an active component in antiviral surfaces or in virucidal formulations. Herein, the most promising strategies reported in the literature on the use of GRM‐based materials against the COVID‐19 pandemic and other types of viruses are showcased, with a strong focus on the impact of functionalization, deposition techniques, and integration into devices and surface coatings.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The graphene revolution, which has taken place during the last 15 years, has represented a paradigm shift for science. The extraordinary properties possessed by this unique material have paved the road to a number of applications in materials science, optoelectronics, energy, and sensing. Graphene‐related materials (GRMs) are now produced in large scale and have found niche applications also in the biomedical technologies, defining new standards for drug delivery and biosensing. Such advances position GRMs as novel tools to fight against the current COVID‐19 and future pandemics. In this regard, GRMs can play a major role in sensing, as an active component in antiviral surfaces or in virucidal formulations. Herein, the most promising strategies reported in the literature on the use of GRM‐based materials against the COVID‐19 pandemic and other types of viruses are showcased, with a strong focus on the impact of functionalization, deposition techniques, and integration into devices and surface coatings. |
Montes-García, V; de Oliveira, Furlan R; andA. Berezin, Wang Y; Fanjul-Bolado, P; García, González M B; Hermans, T M; Bonifazi, D; Casalini, S; Samorì, P Harnessing Selectivity and Sensitivity in Ion Sensing via Supramolecular Recognition: A 3D Hybrid Gold Nanoparticle Network Chemiresistor Article de journal Dans: Adv. Funct. Mater., 31 (2008554), 2021. @article{Montes-García2021b, title = {Harnessing Selectivity and Sensitivity in Ion Sensing via Supramolecular Recognition: A 3D Hybrid Gold Nanoparticle Network Chemiresistor}, author = {V. Montes-García and R. Furlan de Oliveira and Y. Wang andA. Berezin and P. Fanjul-Bolado and M. B. González García and T. M. Hermans and D. Bonifazi and S. Casalini and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/adfm.202008554}, year = {2021}, date = {2021-03-03}, journal = {Adv. Funct. Mater.}, volume = {31}, number = {2008554}, abstract = {The monitoring of K+ in saliva, blood, urine, or sweat represents a future powerful alternative diagnostic tool to prevent various diseases. However, several K+ sensors are unable to meet the requirements for the development of point‐of‐care (POC) sensors. To tackle this grand‐challenge, the fabrication of chemiresistors (CRs) based on 3D networks of Au nanoparticles covalently bridged by ad‐hoc supramolecular receptors for K+, namely dithiomethylene dibenzo‐18‐crown‐6 ether is reported here. A multi‐technique characterization allows optimizing a new protocol for fabricating high‐performing CRs for real‐time monitoring of K+ in complex aqueous environments. The sensor shows exceptional figures of merit: i) linear sensitivity in the 10–3 to 10–6 m concentration range; ii) high selectivity to K+ in presence of interfering cations (Na+, Ca2+, and Mg2+); iii) high shelf‐life stability (>45 days); iv) reversibility of K+ binding and release; v) successful device integration into microfluidic systems for real‐time monitoring; vi) fast response and recovery times (<18 s), and v) K+ detection in artificial saliva. All these characteristics make the supramolecular CRs a potential tool for future applications as POC devices, especially for health monitoring where the determination of K+ in saliva is pivotal for the early diagnosis of diseases.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The monitoring of K+ in saliva, blood, urine, or sweat represents a future powerful alternative diagnostic tool to prevent various diseases. However, several K+ sensors are unable to meet the requirements for the development of point‐of‐care (POC) sensors. To tackle this grand‐challenge, the fabrication of chemiresistors (CRs) based on 3D networks of Au nanoparticles covalently bridged by ad‐hoc supramolecular receptors for K+, namely dithiomethylene dibenzo‐18‐crown‐6 ether is reported here. A multi‐technique characterization allows optimizing a new protocol for fabricating high‐performing CRs for real‐time monitoring of K+ in complex aqueous environments. The sensor shows exceptional figures of merit: i) linear sensitivity in the 10–3 to 10–6 m concentration range; ii) high selectivity to K+ in presence of interfering cations (Na+, Ca2+, and Mg2+); iii) high shelf‐life stability (>45 days); iv) reversibility of K+ binding and release; v) successful device integration into microfluidic systems for real‐time monitoring; vi) fast response and recovery times (<18 s), and v) K+ detection in artificial saliva. All these characteristics make the supramolecular CRs a potential tool for future applications as POC devices, especially for health monitoring where the determination of K+ in saliva is pivotal for the early diagnosis of diseases. |
Ippolito, S; Kelly, A G; de Oliveira, Furlan R; Stoeckel, M -A; Iglesias, D; A. Roy, Downing C; Z. Bian, Lombardi L; Samad, Y A; V. Nicolosi, Ferrari A C; Coleman, J N; Samorì, P Covalently interconnected transition metal dichalcogenide networks via defect engineering for high-performance electronic devices Article de journal Dans: Nat. Nanotechnol., 16 , p. 592–598, 2021. @article{Ippolito2021b, title = {Covalently interconnected transition metal dichalcogenide networks via defect engineering for high-performance electronic devices}, author = {S. Ippolito and A. G. Kelly and R. Furlan de Oliveira and M.-A. Stoeckel and D. Iglesias and A. Roy, C. Downing and Z. Bian, L. Lombardi and Y. A. Samad and V. Nicolosi, A. C. Ferrari and J. N. Coleman and P. Samorì}, editor = {Nature Nanotechnology }, url = {https://doi.org/10.1038/s41565-021-00857-9}, year = {2021}, date = {2021-02-25}, journal = {Nat. Nanotechnol.}, volume = {16}, pages = {592–598}, abstract = {Solution-processed semiconducting transition metal dichalcogenides are at the centre of an ever-increasing research effort in printed (opto)electronics. However, device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity. Here, we report a new molecular strategy to boost the electrical performance of transition metal dichalcogenide-based devices via the use of dithiolated conjugated molecules, to simultaneously heal sulfur vacancies in solution-processed transition metal disulfides and covalently bridge adjacent flakes, thereby promoting percolation pathways for the charge transport. We achieve a reproducible increase by one order of magnitude in field-effect mobility (µFE), current ratio (ION/IOFF) and switching time (τS) for liquid-gated transistors, reaching 10−2 cm2 V−1 s−1, 104 and 18 ms, respectively. Our functionalization strategy is a universal route to simultaneously enhance the electronic connectivity in transition metal disulfide networks and tailor on demand their physicochemical properties according to the envisioned applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Solution-processed semiconducting transition metal dichalcogenides are at the centre of an ever-increasing research effort in printed (opto)electronics. However, device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity. Here, we report a new molecular strategy to boost the electrical performance of transition metal dichalcogenide-based devices via the use of dithiolated conjugated molecules, to simultaneously heal sulfur vacancies in solution-processed transition metal disulfides and covalently bridge adjacent flakes, thereby promoting percolation pathways for the charge transport. We achieve a reproducible increase by one order of magnitude in field-effect mobility (µFE), current ratio (ION/IOFF) and switching time (τS) for liquid-gated transistors, reaching 10−2 cm2 V−1 s−1, 104 and 18 ms, respectively. Our functionalization strategy is a universal route to simultaneously enhance the electronic connectivity in transition metal disulfide networks and tailor on demand their physicochemical properties according to the envisioned applications. |
Huang, C -B; Yao, Y; Montes-García, V; Stoeckel, M -A; Holst, Von M; Ciesielski, A; Samorì, P Highly Sensitive Strain Sensors Based on Molecules–Gold Nanoparticles Networks for High‐Resolution Human Pulse Analysis Article de journal Dans: Small, 17 (2007593), 2021. @article{Huang2021, title = {Highly Sensitive Strain Sensors Based on Molecules–Gold Nanoparticles Networks for High‐Resolution Human Pulse Analysis}, author = {C.-B. Huang and Y. Yao and V. Montes-García and M.-A. Stoeckel and M. Von Holst and A. Ciesielski and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smll.202007593}, year = {2021}, date = {2021-02-24}, journal = {Small}, volume = {17}, number = {2007593}, abstract = {High‐performance flexible strain sensors are key components for the next generation of wearable health monitoring devices. Here, the authors have fabricated a novel strain sensor based on gold nanoparticles (AuNPs) interconnected by flexible and responsive molecular linkers. The combination of conductive AuNPs (25 nm in diameter) with tetra(ethylene glycol) dithiol (SH‐TEG‐SH) linkers yields a covalent 3D network which can be directly deposited onto prepatterned flexible supports exposing interdigitated Au electrodes. The electrically insulating nature of the linkers effectively defines the tunneling modulated charge transfer through the AuNPs network. When compressive/tensile strain is applied, the molecular linkers adopt a compressed/stretched conformation thus decreasing/increasing the interparticle distance, ultimately yielding an exponential increase/decrease of the tunneling current when voltage is applied. The strain sensor displays state‐of‐the‐art performances including a highly sensitive response to both tensile and compressive strain, as quantified by a high gauge factor (GF≈126) combined with other superior sensing properties like high flexibility, short response time (16.1 ms), and good robustness (>2000 cycles). Finally, the applicability of the device for health monitoring is demonstrated: high‐resolution artery pulse waves are acquired by placing the strain sensor onto the skin allowing the extraction of important physical parameters for human‐health assessment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } High‐performance flexible strain sensors are key components for the next generation of wearable health monitoring devices. Here, the authors have fabricated a novel strain sensor based on gold nanoparticles (AuNPs) interconnected by flexible and responsive molecular linkers. The combination of conductive AuNPs (25 nm in diameter) with tetra(ethylene glycol) dithiol (SH‐TEG‐SH) linkers yields a covalent 3D network which can be directly deposited onto prepatterned flexible supports exposing interdigitated Au electrodes. The electrically insulating nature of the linkers effectively defines the tunneling modulated charge transfer through the AuNPs network. When compressive/tensile strain is applied, the molecular linkers adopt a compressed/stretched conformation thus decreasing/increasing the interparticle distance, ultimately yielding an exponential increase/decrease of the tunneling current when voltage is applied. The strain sensor displays state‐of‐the‐art performances including a highly sensitive response to both tensile and compressive strain, as quantified by a high gauge factor (GF≈126) combined with other superior sensing properties like high flexibility, short response time (16.1 ms), and good robustness (>2000 cycles). Finally, the applicability of the device for health monitoring is demonstrated: high‐resolution artery pulse waves are acquired by placing the strain sensor onto the skin allowing the extraction of important physical parameters for human‐health assessment. |
Richard, J; Joseph, J; Wang, C; Ciesielski, A; Weiss, J; Samorì, P; Mamane, V; Wytko, J A Functionalized 4,4′-Bipyridines: Synthesis and 2D Organization on Highly Oriented Pyrolytic Graphite Article de journal Dans: J. Org. Chem., 86 , p. 3356−3366, 2021. @article{Richard2021, title = {Functionalized 4,4′-Bipyridines: Synthesis and 2D Organization on Highly Oriented Pyrolytic Graphite}, author = {J. Richard and J. Joseph and C. Wang and A. Ciesielski and J. Weiss and P. Samorì and V. Mamane and J. A. Wytko}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acs.joc.0c02708}, year = {2021}, date = {2021-02-04}, journal = {J. Org. Chem.}, volume = {86}, pages = {3356−3366}, abstract = {Commercial 4,4′-bipyridine is a popular scaffold that is primarily employed as a linker in 3D self-assembled architectures such as metallo-organic frameworks or as a connector in 2D networks. The introduction of alkyl substituents on the bipyridine skeleton is instrumental when 4,4′-bipyridines are used as linkers to form 2D self-assembled patterns on surfaces. Here, several synthetic strategies to access 4,4′-bipyridines functionalized at various positions are described. These easily scalable reactions have been used to introduce a range of alkyl substituents at positions 2 and 2′ or 3 and 3′ and at positions 2,2′ and 6,6′ in the case of tetra-functionalization. Scanning tunneling microscopy studies of molecular monolayers physisorbed at the graphite–solution interface revealed different supramolecular patterns whose motifs are primarily dictated by the nature and position of the alkyl chains.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Commercial 4,4′-bipyridine is a popular scaffold that is primarily employed as a linker in 3D self-assembled architectures such as metallo-organic frameworks or as a connector in 2D networks. The introduction of alkyl substituents on the bipyridine skeleton is instrumental when 4,4′-bipyridines are used as linkers to form 2D self-assembled patterns on surfaces. Here, several synthetic strategies to access 4,4′-bipyridines functionalized at various positions are described. These easily scalable reactions have been used to introduce a range of alkyl substituents at positions 2 and 2′ or 3 and 3′ and at positions 2,2′ and 6,6′ in the case of tetra-functionalization. Scanning tunneling microscopy studies of molecular monolayers physisorbed at the graphite–solution interface revealed different supramolecular patterns whose motifs are primarily dictated by the nature and position of the alkyl chains. |
Montes-García, V; Squillaci, M A; Diez-Castellnou, M; Ong, Q K; Stellacci, F; Samorì, P Chemical sensing with Au and Ag nanoparticles Article de journal Dans: Chem. Soc. Rev., 50 , p. 1269–1304, 2021. @article{Montes-García2021, title = {Chemical sensing with Au and Ag nanoparticles}, author = {V. Montes-García and M. A. Squillaci and M. Diez-Castellnou and Q. K. Ong and F. Stellacci and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d0cs01112f}, year = {2021}, date = {2021-01-21}, journal = {Chem. Soc. Rev.}, volume = {50}, pages = {1269–1304}, abstract = {Noble metal nanoparticles (NPs) are ideal scaffolds for the fabrication of sensing devices because of their high surface-to-volume ratio combined with their unique optical and electrical properties which are extremely sensitive to changes in the environment. Such characteristics guarantee high sensitivity in sensing processes. Metal NPs can be decorated with ad hoc molecular building blocks which can act as receptors of specific analytes. By pursuing this strategy, and by taking full advantage of the specificity of supramolecular recognition events, highly selective sensing devices can be fabricated. Besides, noble metal NPs can also be a pivotal element for the fabrication of chemical nose/tongue sensors to target complex mixtures of analytes. This review highlights the most enlightening strategies developed during the last decade, towards the fabrication of chemical sensors with either optical or electrical readout combining high sensitivity and selectivity, along with fast response and full reversibility, with special attention to approaches that enable efficient environmental and health monitoring.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Noble metal nanoparticles (NPs) are ideal scaffolds for the fabrication of sensing devices because of their high surface-to-volume ratio combined with their unique optical and electrical properties which are extremely sensitive to changes in the environment. Such characteristics guarantee high sensitivity in sensing processes. Metal NPs can be decorated with ad hoc molecular building blocks which can act as receptors of specific analytes. By pursuing this strategy, and by taking full advantage of the specificity of supramolecular recognition events, highly selective sensing devices can be fabricated. Besides, noble metal NPs can also be a pivotal element for the fabrication of chemical nose/tongue sensors to target complex mixtures of analytes. This review highlights the most enlightening strategies developed during the last decade, towards the fabrication of chemical sensors with either optical or electrical readout combining high sensitivity and selectivity, along with fast response and full reversibility, with special attention to approaches that enable efficient environmental and health monitoring. |
Kovtun, A; Candini, A; Vianelli, A; Boschi, A; Dell’Elce, S; Gobbi, M; Kim, K H; and S. Lara Avila, Samorì P; Affronte, M; Liscio, A; Palermo, V Multiscale Charge Transport in van der Waals Thin Films: Reduced Graphene Oxide as a Case Study Article de journal Dans: ACS Nano, (15), p. 2654–2667, 2021. @article{Kovtun2021, title = {Multiscale Charge Transport in van der Waals Thin Films: Reduced Graphene Oxide as a Case Study}, author = {A. Kovtun and A. Candini and A. Vianelli and A. Boschi and S. Dell’Elce and M. Gobbi and K. H. Kim and S. Lara Avila ,and P. Samorì and M. Affronte and A. Liscio and V. Palermo}, editor = {ACS Publcation}, url = {https://doi.org/10.1021/acsnano.0c07771}, year = {2021}, date = {2021-01-19}, journal = {ACS Nano}, number = {15}, pages = {2654–2667}, abstract = {Large area van der Waals (vdW) thin films are assembled materials consisting of a network of randomly stacked nanosheets. The multiscale structure and the two-dimensional (2D) nature of the building block mean that interfaces naturally play a crucial role in the charge transport of such thin films. While single or few stacked nanosheets (i.e., vdW heterostructures) have been the subject of intensive works, little is known about how charges travel through multilayered, more disordered networks. Here, we report a comprehensive study of a prototypical system given by networks of randomly stacked reduced graphene oxide 2D nanosheets, whose chemical and geometrical properties can be controlled independently, permitting to explore percolated networks ranging from a single nanosheet to some billions with room-temperature resistivity spanning from 10–5 to 10–1 Ω·m. We systematically observe a clear transition between two different regimes at a critical temperature T*: Efros–Shklovskii variable-range hopping (ES-VRH) below T* and power law behavior above. First, we demonstrate that the two regimes are strongly correlated with each other, both depending on the charge localization length ξ, calculated by the ES-VRH model, which corresponds to the characteristic size of overlapping sp2 domains belonging to different nanosheets. Thus, we propose a microscopic model describing the charge transport as a geometrical phase transition, given by the metal–insulator transition associated with the percolation of quasi-one-dimensional nanofillers with length ξ, showing that the charge transport behavior of the networks is valid for all geometries and defects of the nanosheets, ultimately suggesting a generalized description on vdW and disordered thin films.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Large area van der Waals (vdW) thin films are assembled materials consisting of a network of randomly stacked nanosheets. The multiscale structure and the two-dimensional (2D) nature of the building block mean that interfaces naturally play a crucial role in the charge transport of such thin films. While single or few stacked nanosheets (i.e., vdW heterostructures) have been the subject of intensive works, little is known about how charges travel through multilayered, more disordered networks. Here, we report a comprehensive study of a prototypical system given by networks of randomly stacked reduced graphene oxide 2D nanosheets, whose chemical and geometrical properties can be controlled independently, permitting to explore percolated networks ranging from a single nanosheet to some billions with room-temperature resistivity spanning from 10–5 to 10–1 Ω·m. We systematically observe a clear transition between two different regimes at a critical temperature T*: Efros–Shklovskii variable-range hopping (ES-VRH) below T* and power law behavior above. First, we demonstrate that the two regimes are strongly correlated with each other, both depending on the charge localization length ξ, calculated by the ES-VRH model, which corresponds to the characteristic size of overlapping sp2 domains belonging to different nanosheets. Thus, we propose a microscopic model describing the charge transport as a geometrical phase transition, given by the metal–insulator transition associated with the percolation of quasi-one-dimensional nanofillers with length ξ, showing that the charge transport behavior of the networks is valid for all geometries and defects of the nanosheets, ultimately suggesting a generalized description on vdW and disordered thin films. |
Lucas, S; Kammerer, J; Pfannmöller, M; Schröder, R R; He, Y; Li, N; Brabec, C J; Leydecker, T; Samorì, P; Marszalek, T; Pisula, W; Mena-Osteritz, E; Bäuerle, P Molecular Donor–Acceptor Dyads for Efficient Single‐Material Organic Solar Cells Article de journal Dans: Sol. RRL, 5 (1), 2021. @article{Lucas2021, title = {Molecular Donor–Acceptor Dyads for Efficient Single‐Material Organic Solar Cells}, author = {S. Lucas and J. Kammerer and M. Pfannmöller and R. R. Schröder and Y. He and N. Li and C. J. Brabec and T. Leydecker and P. Samorì and T. Marszalek and W. Pisula and E. Mena-Osteritz and P. Bäuerle}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/solr.202000653}, year = {2021}, date = {2021-01-07}, journal = {Sol. RRL}, volume = {5}, number = {1}, abstract = {Single‐material organic solar cells (SMOSCs) promise several advantages with respect to prospective applications in printed large‐area solar foils. Only one photoactive material has to be processed and the impressive thermal and photochemical long‐term stability of the devices is achieved. Herein, a novel structural design of oligomeric donor–acceptor (D–A) dyads 1–3 is established, in which an oligothiophene donor and fullerene acceptor are covalently linked by a flexible spacer of variable length. Favorable optoelectronic, charge transport, and self‐organization properties of the D–A dyads are the basis for reaching power conversion efficiencies up to 4.26% in SMOSCs. The dependence of photovoltaic and charge transport parameters in these ambipolar semiconductors on the specific molecular structure is investigated before and after post‐treatment by solvent vapor annealing. The inner nanomorphology of the photoactive films of the dyads is analyzed with transmission electron microscopy (TEM) and grazing‐incidence wide‐angle X‐ray scattering (GIWAXS). Combined theoretical calculations result in a lamellar supramolecular order of the dyads with a D–A phase separation smaller than 2 nm. The molecular design and the precise distance between donor and acceptor moieties ensure the fundamental physical processes operative in organic solar cells and provide stabilization of D–A interfaces. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Single‐material organic solar cells (SMOSCs) promise several advantages with respect to prospective applications in printed large‐area solar foils. Only one photoactive material has to be processed and the impressive thermal and photochemical long‐term stability of the devices is achieved. Herein, a novel structural design of oligomeric donor–acceptor (D–A) dyads 1–3 is established, in which an oligothiophene donor and fullerene acceptor are covalently linked by a flexible spacer of variable length. Favorable optoelectronic, charge transport, and self‐organization properties of the D–A dyads are the basis for reaching power conversion efficiencies up to 4.26% in SMOSCs. The dependence of photovoltaic and charge transport parameters in these ambipolar semiconductors on the specific molecular structure is investigated before and after post‐treatment by solvent vapor annealing. The inner nanomorphology of the photoactive films of the dyads is analyzed with transmission electron microscopy (TEM) and grazing‐incidence wide‐angle X‐ray scattering (GIWAXS). Combined theoretical calculations result in a lamellar supramolecular order of the dyads with a D–A phase separation smaller than 2 nm. The molecular design and the precise distance between donor and acceptor moieties ensure the fundamental physical processes operative in organic solar cells and provide stabilization of D–A interfaces. |
Yakhlifi, El S; Alfieri, M -L; Arntz, Y; Eredia, M; Ciesielski, A; Samorì, P; d’Ischia, M; Ball, V Oxidant-dependent antioxidant activity of polydopamine films: The chemistry-morphology interplay Article de journal Dans: Colloids Surf. A, 614 (126134), 2021. @article{Yakhlifi2021, title = {Oxidant-dependent antioxidant activity of polydopamine films: The chemistry-morphology interplay}, author = {S. El Yakhlifi and M.-L. Alfieri and Y. Arntz and M. Eredia and A. Ciesielski and P. Samorì and M. d’Ischia and V. Ball}, editor = {Science Direct}, url = {https://doi.org/10.1016/j.colsurfa.2021.126134}, year = {2021}, date = {2021-01-01}, journal = {Colloids Surf. A}, volume = {614}, number = {126134}, abstract = {Polydopamine (PDA) films allow to functionalize almost all materials with a conformal and chemically active coating. These coatings can react with reducible metallic cations and with all kinds of molecules carrying nucleophilic groups. Recently, our team extended PDA chemistry to a vast repertoire of oxidants and to acidic conditions. However, the influence of changes in the method of PDA deposition on the properties of the obtained coatings, in particular the antioxidant properties, have not been sufficiently explored. It is anticipated that the antioxidant properties should depend on the film preparation method. A combination of experimental techniques, atomic force microscopy, cyclic voltammetry and X ray photoelectron spectroscopy are used to relate the antioxidant properties of PDA films to their structural features and to their chemical composition. It is demonstrated that the antioxidant properties of PDA films are not only dependent on the type of the employed oxidant – which can be expected to affect a variable density of oxidizable groups on the surface of PDA - but also on the oxidant film morphology and roughness.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Polydopamine (PDA) films allow to functionalize almost all materials with a conformal and chemically active coating. These coatings can react with reducible metallic cations and with all kinds of molecules carrying nucleophilic groups. Recently, our team extended PDA chemistry to a vast repertoire of oxidants and to acidic conditions. However, the influence of changes in the method of PDA deposition on the properties of the obtained coatings, in particular the antioxidant properties, have not been sufficiently explored. It is anticipated that the antioxidant properties should depend on the film preparation method. A combination of experimental techniques, atomic force microscopy, cyclic voltammetry and X ray photoelectron spectroscopy are used to relate the antioxidant properties of PDA films to their structural features and to their chemical composition. It is demonstrated that the antioxidant properties of PDA films are not only dependent on the type of the employed oxidant – which can be expected to affect a variable density of oxidizable groups on the surface of PDA - but also on the oxidant film morphology and roughness. |
2020 |
Samorì, P; andV. Palermo, Feng X Introduction to ‘Chemistry of 2D materials: graphene and beyond' Article de journal Dans: Nanoscale, 12 , p. 24309–24310, 2020. @article{Samorì2020, title = {Introduction to ‘Chemistry of 2D materials: graphene and beyond'}, author = {P. Samorì and X. Feng andV. Palermo}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d0nr90263b}, year = {2020}, date = {2020-12-10}, journal = {Nanoscale}, volume = {12}, pages = {24309–24310}, abstract = {A graphical abstract is available for this content}, keywords = {}, pubstate = {published}, tppubtype = {article} } A graphical abstract is available for this content |
Janica, I; Iglesias, D; Ippolito, S; Ciesielski, A; Samorì, P Effect of temperature and exfoliation time on the properties of chemically exfoliated MoS2 nanosheets Article de journal Dans: Chem. Commun., 56 , p. 15573–15576, 2020. @article{Janica2020, title = {Effect of temperature and exfoliation time on the properties of chemically exfoliated MoS2 nanosheets}, author = {I. Janica and D. Iglesias and S. Ippolito and A. Ciesielski and P. Samorì}, editor = {Royal Society of Chemistry}, url = {https://doi.org/10.1039/d0cc06792j}, year = {2020}, date = {2020-11-20}, journal = {Chem. Commun.}, volume = {56}, pages = {15573–15576}, abstract = {A systematic investigation of the experimental conditions for the chemical exfoliation of MoS2 using n-butyllithium as intercalating agent has been carried out to unravel the effect of reaction time and temperature for maximizing the percentage of monolayer thick-flakes and achieve a control over the content of metallic 1T vs. semiconductive 2H phases, thereby tuning the electrical properties of ultrathin MoS2 few-layer thick films.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A systematic investigation of the experimental conditions for the chemical exfoliation of MoS2 using n-butyllithium as intercalating agent has been carried out to unravel the effect of reaction time and temperature for maximizing the percentage of monolayer thick-flakes and achieve a control over the content of metallic 1T vs. semiconductive 2H phases, thereby tuning the electrical properties of ultrathin MoS2 few-layer thick films. |
Yao, Y; Chen, Y; Wang, H; Samorì, P Organic photodetectors based on supramolecular nanostructures Article de journal Dans: SmartMat, 1 (1), 2020. @article{Yao2020, title = {Organic photodetectors based on supramolecular nanostructures}, author = {Y. Yao and Y. Chen and H. Wang and P. Samorì}, editor = {Wiley Online Library}, url = {https://doi.org/10.1002/smm2.1009}, year = {2020}, date = {2020-11-08}, journal = {SmartMat}, volume = {1}, number = {1}, abstract = {Self‐assembly of semiconducting (macro)molecules enables the development of materials with tailored‐made properties which could be used as active components for optoelectronics applications. Supramolecular nanostructures combine the merits of soft matter and crystalline materials: They are flexible yet highly crystalline, and they can be processed with low‐cost solution methods. Photodetectors are devices capable to convert a light input into an electrical signal. To achieve high photoresponse, the photogenerated charge carriers should be transported efficiently through the self‐assembled nanostructures to reach the electrodes; this can be guaranteed via optimal π–electron overlapping between adjacent conjugated molecules. Moreover, because of the high surface‐to‐bulk ratio, supramolecular nanostructures are prone to enhance exciton dissociation. These qualities make supramolecular nanostructures perfect platforms for photoelectric conversion. This review highlights the most enlightening recent strategies developed for the fabrication of high‐performance photodetectors based on supramolecular nanostructures. We introduce the key figure‐of‐merit parameters and working mechanisms of organic photodetectors based on single components and p–n heterojunctions. In particular, we describe new methods to devise unprecedented planar and vertical devices to ultimately realize highly integrated and flexible photodetectors. The incorporation of ordered mesoscopic supramolecular nanostructures into macroscopic optoelectronic devices will offer great promise for the next generation of multifunctional and multiresponsive devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Self‐assembly of semiconducting (macro)molecules enables the development of materials with tailored‐made properties which could be used as active components for optoelectronics applications. Supramolecular nanostructures combine the merits of soft matter and crystalline materials: They are flexible yet highly crystalline, and they can be processed with low‐cost solution methods. Photodetectors are devices capable to convert a light input into an electrical signal. To achieve high photoresponse, the photogenerated charge carriers should be transported efficiently through the self‐assembled nanostructures to reach the electrodes; this can be guaranteed via optimal π–electron overlapping between adjacent conjugated molecules. Moreover, because of the high surface‐to‐bulk ratio, supramolecular nanostructures are prone to enhance exciton dissociation. These qualities make supramolecular nanostructures perfect platforms for photoelectric conversion. This review highlights the most enlightening recent strategies developed for the fabrication of high‐performance photodetectors based on supramolecular nanostructures. We introduce the key figure‐of‐merit parameters and working mechanisms of organic photodetectors based on single components and p–n heterojunctions. In particular, we describe new methods to devise unprecedented planar and vertical devices to ultimately realize highly integrated and flexible photodetectors. The incorporation of ordered mesoscopic supramolecular nanostructures into macroscopic optoelectronic devices will offer great promise for the next generation of multifunctional and multiresponsive devices. |
