Fabiola Liscio - Academia.edu (original) (raw)
Papers by Fabiola Liscio
Advanced Materials, Oct 1, 2017
ACS Applied Materials & Interfaces, Mar 1, 2016
Responsive polymer materials can change their properties when subjected to external stimuli. In t... more Responsive polymer materials can change their properties when subjected to external stimuli. In this work, thin films of thermotropic poly(metha)acrylate/azobenzene polymers are explored as active layer in light-programmable, electrically-readable memories. The memory effect is based on the reversible modifications of the film morphology induced by the photo-isomerization of azobenzene mesogenic groups. When the film is in the liquid crystalline phase, the trans→cis isomerization induces a major surface reorganization on the mesoscopic scale that is characterized by a reduction in the effective thickness of the film. The film conductivity is measured in vertical two-terminal devices in which the polymer is sandwiched between an Au contact and a liquid compliant E-GaIn drop. We demonstrate that the
Advanced Materials, Jul 25, 2017
Oxygen gas is the second most common component of the Earth's atmosphere and plays a fundamental ... more Oxygen gas is the second most common component of the Earth's atmosphere and plays a fundamental role in cellular respiration as well as in industrial processes. [1] Therefore the design of oxygen sensors featuring high sensitivity and selectivity, fast response and longterm stability is essential in many fields of science and technology. A promising route to achieve this objective is to use nanostructured materials, i.e. materials with at least one dimension with a characteristic length scale on the 1-100 nm scale, such as porous materials, nanowires or nanoparticles, as active components. [2] Thanks to their characteristic high surface-to-volume ratio, this class of materials can be extremely sensitive to specific variation
Chemistry of Materials, Dec 24, 2018
Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and... more Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and logic applications. Field-effect transistors built on solution-processable ambipolar materials hold strong promise for the engineering of large-area low-cost logic circuits with a reduced number of devices components. Such devices still suffer from a number of obstacles including the challenging processing, the low Ion/Ioff, the unbalanced mobility and the low gain in CMOS-like circuits. Here, we demonstrate that the simple approach of blending commercially available n-and p-type polymers such as P(NDI2OD-T2), P3HT, PCD-TPT, PDVT-8 and IIDDT-C3 can yield high-performing ambipolar field-effect transistors with balanced mobilities and Ion/Ioff >10 7. Each single component was studied separately and upon blending by means of electrical characterization, ambient UPS, AFM and GIWAXS to unravel the correlation between the morphology/structure of the semiconducting films and their functions. Blends of n-and p-type semiconductors were used to fabricate CMOS-like inverter circuits with state-of-the-art gains over 160 in the case of P(NDI2OD-T2) blended with PDVT-8. Significantly, our blending approach was successful in producing semiconducting films with balanced mobilities for each of the 4 tested semiconductor blends although the films displayed different structural and morphological features. Our strategy, which relies on establishing a correlation between ambipolar performances, film morphology, molecular structure and blending ratio, is extremely efficient and versatile, thus it could be applied to a wide range of polymers or solution processable small molecules. ASSOCIATED CONTENT Supporting Information. Experimental details and additional data including electrical characterization, AFM, A-UPS, GIWAXS are available in the supporting information. This material is available free of charge via the Internet at http://pubs.acs.org.
Advanced Materials, Feb 25, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Advanced Materials, Jan 23, 2017
arXiv (Cornell University), Sep 11, 2019
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both intrinsic and extrinsic, especially for n-type materials. Intrinsic 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 renders 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 extrinsic, being controlled by the gate insulator dielectric properties. Here we report on 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. We provide unambiguous evidence that ad hoc molecular design enables to free the electron charge carriers from both intrinsic and extrinsic disorder to ultimately reach band-like electron transport.
Protective hard films on soft inorganic/organic substrates are appealing for several technologica... more Protective hard films on soft inorganic/organic substrates are appealing for several technological applications like solar cells, organic electronics, fuel cells, etc. The main concern is still related to the bad quality of the interface and to the weak mechanical properties of the film as a consequence of the low working temperatures mandatory to prevent substrate softening/melting. Our research activity at Rizzoli Orthopaedic Institute is mainly directed toward the deposition of functional ceramic thin films to improve the mechanical properties (and thus the clinical performances) of the load-bearing plastic component of the prosthetic implant. To this aim, we use a novel sputter-based electron deposition technique named Pulsed Plasma Deposition (PPD) able to provide nanostructured ceramic thin films highly adhered to the plastic substrate and with optimum mechanical performances even if working at room temperature and using very-soft substrates.
Journal of Bone and Joint Surgery-british Volume, 2016
Introduction Protective hard coatings are appealing for several technological applications like s... more Introduction Protective hard coatings are appealing for several technological applications like solar cells, organic electronics, fuel cells, cutting tools and even for orthopaedic implants and prosthetic devices. At present for what concerns the application to prosthetic components, the coating of the surface of the metallic part with low-friction and low-wear materials has been proposed [1]. Concerning the use of ceramic materials in joint arthroplasty, zirconia-toughned-alumina (ZTA) reported high strength, fracture toughness, elasticity, hardness, and wear resistance [2]. The main goal of this study was to directly deposit ZTA coating by using a novel sputter-based electron deposition technique, namely Pulsed Plasma Deposition (PPD) [3]. The realized coatings have been preliminary characterized from the point of view of morphology, wettability, adhesion and friction coefficients. Materials and methods ZTA coatings were deposited by PPD technique, which is able to maintain the stoichiometry of the starting target. In this case we started from a cylindrical ZTA target (30 mm diameter × 5 mm thickness, 75% alumina / 25% zirconia). The morphology, micro-structure and chemistry of deposited coatings were characterized by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray Spectrosopy (EDS) and Atomic Force Microcscope (AFM). Coating-substrate interface quality were investigated by microscratch tests. The degree of wetting was estimated by measuring the contact angle between a drop of 1 ml of ultrapure water and the surface of the sample. Preliminary ball-on-disk tribological tests were carried out in air and deionized water coupling ZTA-coated stainless steel ball (AISI 420, 3 mm radius, grade 200) against medical grade UHMWPE to evaluate the friction of the proposed coupling. Results Deposited ZTA films exhibited a smooth nanostructured surface. Coatings up to several microns thick have been deposited by PPD [Fig. 1 – SEM image (left) and cross section (right)]. Mechanical tests showed a well-adherent films were deposited. In particular, the good interface adhesion was assessed by scratch tests, reporting at about 0.8 N the first formation of cracking in the coating during testing. The contact angles revealed an hydrophobic behavior of the coating (average contact angle 116° ± 2°), probably due to the nano-roughness of the coating itself [Fig. 2 – Contact angle]. Preliminary tribological tests carried out in deionized water after up to 10000 m tracks showed good average friction coefficient ranging from 0.12 to 0.15 [Fig. 3 – Friction coefficient]. Conclusions We have presented the preliminary results of a novel approach aiming to the drastically improve the performance of prosthetic couplings by introducing hard ceramic coating. The results showed suggested the feasibility of pursuing this approach of realizing ZTA coatings by means of PPD technique. Further analyese on mechanical properties, nano-roughness and tribology should be performed. Well-adherent ZTA films deposited directly on the surface of prosthetic components of a joint implant would then allow a drastic improvement of the actual prosthetic behaviour.
arXiv: Materials Science, 2019
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both intrinsic and extrinsic, especially for n-type materials. Intrinsic 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 renders 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 extrinsic, being controlled by the gate insulator dielectric properties. Here we report on a comprehensive study of charge transport in two closely related n-type molecular organic semiconductors using a combination of temperature-dependent inelastic ...
Advanced Materials, 2021
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more 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 (
ACS Applied Electronic Materials, 2019
Nanoscale, 2018
Production and characterization of metal–organic self-assemblies with tuned structures triggered ... more Production and characterization of metal–organic self-assemblies with tuned structures triggered by solvent-vapor annealing.
Advanced materials (Deerfield Beach, Fla.), 2017
Nanostructured materials characterized by high surface-volume ratio hold the promise to constitut... more Nanostructured materials characterized by high surface-volume ratio hold the promise to constitute the active materials for next-generation sensors. Solution-processed hybrid organohalide perovskites, which have been extensively used in the last few years for optoelectronic applications, are characterized by a self-assembled nanostructured morphology, which makes them an ideal candidate for gas sensing. Hitherto, detailed studies of the dependence of their electrical characteristics on the environmental atmosphere have not been performed, and even the effect of a ubiquitous gas such as Ohas been widely overlooked. Here, the electrical response of organohalide perovskites to oxygen is studied. Surprisingly, a colossal increase (3000-fold) in the resistance of perovskite-based lateral devices is found when measured in a full oxygen atmosphere, which is ascribed to a trap healing mechanism originating from an O-mediated iodine vacancies filling. A variation as small as 70 ppm in the ox...
Journal of Luminescence, 2017
Photoexcited ultra-thin films of the organic semiconductor N,N'-bis(n-octyl)-dicyanoperylene-3,4:... more Photoexcited ultra-thin films of the organic semiconductor N,N'-bis(n-octyl)-dicyanoperylene-3,4:9,10bis dicarboximide (DPI8-CN2), grown on thermal Si/SiO 2 , exhibit an intense room temperature emission, strongly dependent on molecular coverage, even for sub-monolayer thicknesses. The luminescence spectra are characterized by a highly structured, isolated molecule emission in the sub-monolayer regime (coverage o30%) and by a condensed-state singlet exciton fluorescence temporally evolving (within 0.5 ns) toward an unstructured, energetically relaxed, excimer-like emission, for thicker films. Once a complete monolayer is formed, only the unstructured excimer emission can be detected. The experimental findings are interpreted in terms of progressive deposition of nearly not interacting molecules, followed by islands formation where a strong dimeric coupling takes place, upon increasing the coverage. A thorough investigation by means of AFM and in-situ X-ray diffraction confirms the proposed picture. & 2017 Elsevier B.V. All rights reserved. λ$630 nm), progressively relaxing to a pair-like excimer emission (for λZ675 nm), which gains intensity on the low energy side of the spectrum, whilst the monomer-like emission correspondingly decreases. By a further increasing of coverage, the film emission Contents lists available at ScienceDirect
![Research paper thumbnail of Synthesis and investigation on processing-depending polarized fluorescence emission in thin-films of 2,2'-([2,2'-Bithiophene]-5,5'-diyl)bis(5-octyl-4-phenyl-4H-thieno[2,3-c]pyrrol-6(5H)-one)](https://attachments.academia-assets.com/115633568/thumbnails/1.jpg)
](J. Mater. Chem. C, 2017
Thienopyrrole-dione (TI) end capped materials have recently emerged as polymorphic molecular semi... more Thienopyrrole-dione (TI) end capped materials have recently emerged as polymorphic molecular semiconductors suitable as active layers of ambipolar light emitting transistors, photovoltaic cells and time temperature integrator devices. Here, we...
Materials Letters, 2017
In orthopedics and dentistry, novel approaches for fabricating biomimetic and mechanically robust... more In orthopedics and dentistry, novel approaches for fabricating biomimetic and mechanically robust bioactive coatings are highly desirable in order to truly improve the clinical results of coated implants compared to uncoated ones. In this paper, a biological-like apatite coating is deposited for the first time by plasma-assisted deposition of a natural apatite source. Specifically, we deposited bone apatite-like (BAL) thin films from bone apatite targets by pulsed electron deposition (PED). Morphology, composition, structure and mechanical properties of as-deposited and annealed BAL and stoichiometric hydroxyapatite (HA) films were investigated. While as-deposited BAL and HA films were poorly crystalline at room temperature, they crystallized to an extent very close to that of natural apatite when annealed at 400 °C. In addition, FTIR analysis pointed out that BAL films closely resembled the composition of the starting natural apatite target. Finally, nanoindentation tests indicated that BAL films with high mechanical properties could be deposited by PED.
ACS nano, 2017
Achieving nanoscale control over the crystalline structure and morphology of electroactive polyme... more Achieving nanoscale control over the crystalline structure and morphology of electroactive polymer films and the possibility to transfer them onto any solid substrate are important tasks for the fabrication of high-performance organic/polymeric field-effect transistors (FETs). In this work, we demonstrate that ultrathin active layers preassembled at the water/air interface can possess high, anisotropic, and substrate-independent mobility in polymer FETs. By exploiting a modified approach to the Langmuir-Schaeffer technique, we self-assemble conjugated polymers in fibrillar structures possessing controlled thickness, nanoscale structure, and morphology; these highly ordered nanofibrils can be transferred unaltered onto any arbitrary substrate. We show that FETs based on these films possess high and anisotropic hole mobility approaching 1 cm(2) V(-1) s(-1) along the nanofibrils, being over 1 order of magnitude beyond the state-of-the-art for Langmuir-Schaefer polymer FETs. Significant...
Advanced materials (Deerfield Beach, Fla.), Jan 23, 2017
Crystalline dioctyl-3,4,9,10-perylenedicarboximide nanowires and 6,13-bis(triisopropylsilylethyny... more Crystalline dioctyl-3,4,9,10-perylenedicarboximide nanowires and 6,13-bis(triisopropylsilylethynyl) pentacene microplates are integrated into a vertical-yet-open asymmetrical heterojunction for the realization of a high-performance organic photovoltaic detector, which shows fast photoresponse, ultrahigh signal-to-noise ratio, and high sensitivity to weak light.
Advanced Materials, Oct 1, 2017
ACS Applied Materials & Interfaces, Mar 1, 2016
Responsive polymer materials can change their properties when subjected to external stimuli. In t... more Responsive polymer materials can change their properties when subjected to external stimuli. In this work, thin films of thermotropic poly(metha)acrylate/azobenzene polymers are explored as active layer in light-programmable, electrically-readable memories. The memory effect is based on the reversible modifications of the film morphology induced by the photo-isomerization of azobenzene mesogenic groups. When the film is in the liquid crystalline phase, the trans→cis isomerization induces a major surface reorganization on the mesoscopic scale that is characterized by a reduction in the effective thickness of the film. The film conductivity is measured in vertical two-terminal devices in which the polymer is sandwiched between an Au contact and a liquid compliant E-GaIn drop. We demonstrate that the
Advanced Materials, Jul 25, 2017
Oxygen gas is the second most common component of the Earth's atmosphere and plays a fundamental ... more Oxygen gas is the second most common component of the Earth's atmosphere and plays a fundamental role in cellular respiration as well as in industrial processes. [1] Therefore the design of oxygen sensors featuring high sensitivity and selectivity, fast response and longterm stability is essential in many fields of science and technology. A promising route to achieve this objective is to use nanostructured materials, i.e. materials with at least one dimension with a characteristic length scale on the 1-100 nm scale, such as porous materials, nanowires or nanoparticles, as active components. [2] Thanks to their characteristic high surface-to-volume ratio, this class of materials can be extremely sensitive to specific variation
Chemistry of Materials, Dec 24, 2018
Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and... more Ambipolar semiconductors are attracting a great interest as building blocks for photovoltaics and logic applications. Field-effect transistors built on solution-processable ambipolar materials hold strong promise for the engineering of large-area low-cost logic circuits with a reduced number of devices components. Such devices still suffer from a number of obstacles including the challenging processing, the low Ion/Ioff, the unbalanced mobility and the low gain in CMOS-like circuits. Here, we demonstrate that the simple approach of blending commercially available n-and p-type polymers such as P(NDI2OD-T2), P3HT, PCD-TPT, PDVT-8 and IIDDT-C3 can yield high-performing ambipolar field-effect transistors with balanced mobilities and Ion/Ioff >10 7. Each single component was studied separately and upon blending by means of electrical characterization, ambient UPS, AFM and GIWAXS to unravel the correlation between the morphology/structure of the semiconducting films and their functions. Blends of n-and p-type semiconductors were used to fabricate CMOS-like inverter circuits with state-of-the-art gains over 160 in the case of P(NDI2OD-T2) blended with PDVT-8. Significantly, our blending approach was successful in producing semiconducting films with balanced mobilities for each of the 4 tested semiconductor blends although the films displayed different structural and morphological features. Our strategy, which relies on establishing a correlation between ambipolar performances, film morphology, molecular structure and blending ratio, is extremely efficient and versatile, thus it could be applied to a wide range of polymers or solution processable small molecules. ASSOCIATED CONTENT Supporting Information. Experimental details and additional data including electrical characterization, AFM, A-UPS, GIWAXS are available in the supporting information. This material is available free of charge via the Internet at http://pubs.acs.org.
Advanced Materials, Feb 25, 2021
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Advanced Materials, Jan 23, 2017
arXiv (Cornell University), Sep 11, 2019
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both intrinsic and extrinsic, especially for n-type materials. Intrinsic 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 renders 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 extrinsic, being controlled by the gate insulator dielectric properties. Here we report on 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. We provide unambiguous evidence that ad hoc molecular design enables to free the electron charge carriers from both intrinsic and extrinsic disorder to ultimately reach band-like electron transport.
Protective hard films on soft inorganic/organic substrates are appealing for several technologica... more Protective hard films on soft inorganic/organic substrates are appealing for several technological applications like solar cells, organic electronics, fuel cells, etc. The main concern is still related to the bad quality of the interface and to the weak mechanical properties of the film as a consequence of the low working temperatures mandatory to prevent substrate softening/melting. Our research activity at Rizzoli Orthopaedic Institute is mainly directed toward the deposition of functional ceramic thin films to improve the mechanical properties (and thus the clinical performances) of the load-bearing plastic component of the prosthetic implant. To this aim, we use a novel sputter-based electron deposition technique named Pulsed Plasma Deposition (PPD) able to provide nanostructured ceramic thin films highly adhered to the plastic substrate and with optimum mechanical performances even if working at room temperature and using very-soft substrates.
Journal of Bone and Joint Surgery-british Volume, 2016
Introduction Protective hard coatings are appealing for several technological applications like s... more Introduction Protective hard coatings are appealing for several technological applications like solar cells, organic electronics, fuel cells, cutting tools and even for orthopaedic implants and prosthetic devices. At present for what concerns the application to prosthetic components, the coating of the surface of the metallic part with low-friction and low-wear materials has been proposed [1]. Concerning the use of ceramic materials in joint arthroplasty, zirconia-toughned-alumina (ZTA) reported high strength, fracture toughness, elasticity, hardness, and wear resistance [2]. The main goal of this study was to directly deposit ZTA coating by using a novel sputter-based electron deposition technique, namely Pulsed Plasma Deposition (PPD) [3]. The realized coatings have been preliminary characterized from the point of view of morphology, wettability, adhesion and friction coefficients. Materials and methods ZTA coatings were deposited by PPD technique, which is able to maintain the stoichiometry of the starting target. In this case we started from a cylindrical ZTA target (30 mm diameter × 5 mm thickness, 75% alumina / 25% zirconia). The morphology, micro-structure and chemistry of deposited coatings were characterized by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray Spectrosopy (EDS) and Atomic Force Microcscope (AFM). Coating-substrate interface quality were investigated by microscratch tests. The degree of wetting was estimated by measuring the contact angle between a drop of 1 ml of ultrapure water and the surface of the sample. Preliminary ball-on-disk tribological tests were carried out in air and deionized water coupling ZTA-coated stainless steel ball (AISI 420, 3 mm radius, grade 200) against medical grade UHMWPE to evaluate the friction of the proposed coupling. Results Deposited ZTA films exhibited a smooth nanostructured surface. Coatings up to several microns thick have been deposited by PPD [Fig. 1 – SEM image (left) and cross section (right)]. Mechanical tests showed a well-adherent films were deposited. In particular, the good interface adhesion was assessed by scratch tests, reporting at about 0.8 N the first formation of cracking in the coating during testing. The contact angles revealed an hydrophobic behavior of the coating (average contact angle 116° ± 2°), probably due to the nano-roughness of the coating itself [Fig. 2 – Contact angle]. Preliminary tribological tests carried out in deionized water after up to 10000 m tracks showed good average friction coefficient ranging from 0.12 to 0.15 [Fig. 3 – Friction coefficient]. Conclusions We have presented the preliminary results of a novel approach aiming to the drastically improve the performance of prosthetic couplings by introducing hard ceramic coating. The results showed suggested the feasibility of pursuing this approach of realizing ZTA coatings by means of PPD technique. Further analyese on mechanical properties, nano-roughness and tribology should be performed. Well-adherent ZTA films deposited directly on the surface of prosthetic components of a joint implant would then allow a drastic improvement of the actual prosthetic behaviour.
arXiv: Materials Science, 2019
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of disorder, both intrinsic and extrinsic, especially for n-type materials. Intrinsic 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 renders 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 extrinsic, being controlled by the gate insulator dielectric properties. Here we report on a comprehensive study of charge transport in two closely related n-type molecular organic semiconductors using a combination of temperature-dependent inelastic ...
Advanced Materials, 2021
Charge transport in organic semiconductors is notoriously extremely sensitive to the presence of ... more 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 (
ACS Applied Electronic Materials, 2019
Nanoscale, 2018
Production and characterization of metal–organic self-assemblies with tuned structures triggered ... more Production and characterization of metal–organic self-assemblies with tuned structures triggered by solvent-vapor annealing.
Advanced materials (Deerfield Beach, Fla.), 2017
Nanostructured materials characterized by high surface-volume ratio hold the promise to constitut... more Nanostructured materials characterized by high surface-volume ratio hold the promise to constitute the active materials for next-generation sensors. Solution-processed hybrid organohalide perovskites, which have been extensively used in the last few years for optoelectronic applications, are characterized by a self-assembled nanostructured morphology, which makes them an ideal candidate for gas sensing. Hitherto, detailed studies of the dependence of their electrical characteristics on the environmental atmosphere have not been performed, and even the effect of a ubiquitous gas such as Ohas been widely overlooked. Here, the electrical response of organohalide perovskites to oxygen is studied. Surprisingly, a colossal increase (3000-fold) in the resistance of perovskite-based lateral devices is found when measured in a full oxygen atmosphere, which is ascribed to a trap healing mechanism originating from an O-mediated iodine vacancies filling. A variation as small as 70 ppm in the ox...
Journal of Luminescence, 2017
Photoexcited ultra-thin films of the organic semiconductor N,N'-bis(n-octyl)-dicyanoperylene-3,4:... more Photoexcited ultra-thin films of the organic semiconductor N,N'-bis(n-octyl)-dicyanoperylene-3,4:9,10bis dicarboximide (DPI8-CN2), grown on thermal Si/SiO 2 , exhibit an intense room temperature emission, strongly dependent on molecular coverage, even for sub-monolayer thicknesses. The luminescence spectra are characterized by a highly structured, isolated molecule emission in the sub-monolayer regime (coverage o30%) and by a condensed-state singlet exciton fluorescence temporally evolving (within 0.5 ns) toward an unstructured, energetically relaxed, excimer-like emission, for thicker films. Once a complete monolayer is formed, only the unstructured excimer emission can be detected. The experimental findings are interpreted in terms of progressive deposition of nearly not interacting molecules, followed by islands formation where a strong dimeric coupling takes place, upon increasing the coverage. A thorough investigation by means of AFM and in-situ X-ray diffraction confirms the proposed picture. & 2017 Elsevier B.V. All rights reserved. λ$630 nm), progressively relaxing to a pair-like excimer emission (for λZ675 nm), which gains intensity on the low energy side of the spectrum, whilst the monomer-like emission correspondingly decreases. By a further increasing of coverage, the film emission Contents lists available at ScienceDirect
J. Mater. Chem. C, 2017
Thienopyrrole-dione (TI) end capped materials have recently emerged as polymorphic molecular semi... more Thienopyrrole-dione (TI) end capped materials have recently emerged as polymorphic molecular semiconductors suitable as active layers of ambipolar light emitting transistors, photovoltaic cells and time temperature integrator devices. Here, we...
Materials Letters, 2017
In orthopedics and dentistry, novel approaches for fabricating biomimetic and mechanically robust... more In orthopedics and dentistry, novel approaches for fabricating biomimetic and mechanically robust bioactive coatings are highly desirable in order to truly improve the clinical results of coated implants compared to uncoated ones. In this paper, a biological-like apatite coating is deposited for the first time by plasma-assisted deposition of a natural apatite source. Specifically, we deposited bone apatite-like (BAL) thin films from bone apatite targets by pulsed electron deposition (PED). Morphology, composition, structure and mechanical properties of as-deposited and annealed BAL and stoichiometric hydroxyapatite (HA) films were investigated. While as-deposited BAL and HA films were poorly crystalline at room temperature, they crystallized to an extent very close to that of natural apatite when annealed at 400 °C. In addition, FTIR analysis pointed out that BAL films closely resembled the composition of the starting natural apatite target. Finally, nanoindentation tests indicated that BAL films with high mechanical properties could be deposited by PED.
ACS nano, 2017
Achieving nanoscale control over the crystalline structure and morphology of electroactive polyme... more Achieving nanoscale control over the crystalline structure and morphology of electroactive polymer films and the possibility to transfer them onto any solid substrate are important tasks for the fabrication of high-performance organic/polymeric field-effect transistors (FETs). In this work, we demonstrate that ultrathin active layers preassembled at the water/air interface can possess high, anisotropic, and substrate-independent mobility in polymer FETs. By exploiting a modified approach to the Langmuir-Schaeffer technique, we self-assemble conjugated polymers in fibrillar structures possessing controlled thickness, nanoscale structure, and morphology; these highly ordered nanofibrils can be transferred unaltered onto any arbitrary substrate. We show that FETs based on these films possess high and anisotropic hole mobility approaching 1 cm(2) V(-1) s(-1) along the nanofibrils, being over 1 order of magnitude beyond the state-of-the-art for Langmuir-Schaefer polymer FETs. Significant...
Advanced materials (Deerfield Beach, Fla.), Jan 23, 2017
Crystalline dioctyl-3,4,9,10-perylenedicarboximide nanowires and 6,13-bis(triisopropylsilylethyny... more Crystalline dioctyl-3,4,9,10-perylenedicarboximide nanowires and 6,13-bis(triisopropylsilylethynyl) pentacene microplates are integrated into a vertical-yet-open asymmetrical heterojunction for the realization of a high-performance organic photovoltaic detector, which shows fast photoresponse, ultrahigh signal-to-noise ratio, and high sensitivity to weak light.