A5069150117- 2D Materials and Applications
- Graphene research and applications
- Nanowire Synthesis and Applications
- MXene and MAX Phase Materials
- Molecular Junctions and Nanostructures
- Semiconductor materials and interfaces
- Advanced Memory and Neural Computing
- Advanced Sensor and Energy Harvesting Materials
- Advancements in Semiconductor Devices and Circuit Design
- Semiconductor Quantum Structures and Devices
- Chalcogenide Semiconductor Thin Films
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- Carbon Nanotubes in Composites
- Semiconductor materials and devices
- Photonic and Optical Devices
- Thermal properties of materials
- ZnO doping and properties
- Astrophysics and Cosmic Phenomena
- Mechanical Behavior of Composites
- Metal Forming Simulation Techniques
- Polymer Nanocomposite Synthesis and Irradiation
- Dark Matter and Cosmic Phenomena
- Magnetic and transport properties of perovskites and related materials
- Ga2O3 and related materials
Drexel University
2025
Centre National de la Recherche Scientifique
2023-2025
Université de Strasbourg
2023-2025
Mercedes-Benz (Germany)
2023
Czech Academy of Sciences, Institute of Physics
2019-2022
Czech Academy of Sciences
2019-2022
National Research Council
2019-2021
University of Salerno
2018-2021
Superconducting and other Innovative Materials and Devices Institute
2019-2021
University of L'Aquila
2020
We discuss the high-bias electrical characteristics of back-gated field-effect transistors with CVD-synthesized bilayer MoS2 channel and Ti Schottky contacts. find that oxidized contacts on form rectifying junctions ~0.3 to 0.5 eV barrier height. To explain output transistors, we propose a model based two slightly asymmetric back-to-back barriers, where highest current arises from image force lowering at electrically forced junction, while reverse is due Schottky-barrier limited injection...
Field emission electron sources in vacuum electronics are largely considered to achieve faster response, higher efficiency and lower energy consumption comparison with conventional thermionic emitters. Carbon nanotubes had a leading role renewing attention field technologies the early 1990s, due their exceptional emitting properties enabled by large aspect ratio, high electrical conductivity, thermal chemical stability. In last decade, search for improved emitters has been extended several...
We demonstrate a back-gate modulated field-emission current from WSe<sub>2</sub> monolayer and propose new vertical transistor concept.
We study the effect of electric stress, gas pressure and type on hysteresis in transfer characteristics monolayer molybdenum disulfide (MoS2) field transistors. The presence defects point vacancies MoS2 crystal structure facilitates adsorption oxygen, nitrogen, hydrogen or methane, which strongly affect transistor electrical characteristics. Although does not modify conduction type, we demonstrate a correlation between width energy onto surface. show that is controllable by and/or type....
Abstract The metal-graphene contact resistance is one of the major limiting factors toward technological exploitation graphene in electronic devices and sensors. High can be detrimental to device performance spoil intrinsic great properties graphene. In this paper, we fabricate back-gate field-effect transistors with different geometries study channel as well carrier mobility a function gate voltage temperature. We apply transfer length method y-function showing that two approaches...
We study the electrical transport in back-gate field-effect transistors with ultrathin palladium diselenide (PdSe2) channel. The devices are normally-on and exhibit dominant n-type conduction at low pressure. electron conduction, combined sharp edge workfunction decreasing number of layers, opens way to applications PdSe2 nanosheets vacuum electronics. In this work, we demonstrate field emission from few-layer current up uA turn-on below 100 V/um, thus extending plethora recently isolated...
Transition metal carbides and nitrides (MXenes) are an emerging class of 2D materials, which attracting ever-growing attention due to their remarkable physicochemical properties. The presence various surface functional groups on MXenes' surface, e.g., F, O, OH, Cl, opens the possibility tune properties through chemical functionalization approaches. However, only a few methods have been explored for covalent MXenes include diazonium salt grafting silylation reactions. Here, unprecedented...
We present the optoelectronic characterization of two graphene/silicon Schottky junctions, fabricated by transferring CVD-graphene on flat and nanotip-patterned n-Si substrates, respectively. demonstrate record photo responsivity, exceeding 2.5 A/W under white light, which we attribute to contribution charges photogenerated in surrounding region junction or internal gain impact ionization caused enhanced field nanotips.
We report the electrical characterization and field emission properties of MoS 2 bilayers deposited on a SiO / Si substrate. Current-voltage characteristics are measured in back-gate transistor configuration, with Ti contacts patterned by electron beam lithography. confirm n-type character as-grown we normally-on field-effect transistors. Local is performed inside scanning microscope chamber piezo-controlled tungsten tips working as anode cathode. demonstrate that an electric ~ 200 V μ m...
A few-layer palladium diselenide (PdSe2) field effect transistor is studied under external stimuli such as electrical and optical fields, electron irradiation gas pressure. We observe ambipolar conduction hysteresis in the transfer curves of PdSe2 material unprotected as-exfoliated. tune its hysteretic behavior air pure nitrogen environments. The prevailing p-type transport observed at room pressure reversibly turned into dominant n-type by reducing pressure, which can simultaneously...
We study the effect of polymer coating, pressure, temperature, and light on electrical characteristics monolayer WSe 2 back-gated transistors with Ni / Au contacts. Our investigation shows that removal a layer poly(methyl methacrylate) (PMMA) or decrease pressure change device conductivity from p- to n-type. From temperature behavior transistor transfer characteristics, gate-tunable Schottky barrier at contacts is demonstrated height ~ 70 meV in flat-band condition measured. also report...
Electrical characterization of few-layer MoS2 based field effect transistors with Ti/Au electrodes is performed in the vacuum chamber a scanning electron microscope order to study effects beam irradiation on transport properties device. A negative threshold voltage shift and carrier mobility enhancement observed explained terms positive charges trapped SiO2 gate oxide, during irradiation. The transistor channel current increased up three magnitudes after exposure an dose 100e-/nm2. Finally,...
Metal contacts play a fundamental role in nanoscale devices. In this work, Schottky metal monolayer molybdenum disulfide (MoS2) field-effect transistors are investigated under electron beam irradiation. It is shown that the exposure of Ti/Au source/drain electrodes to an reduces contact resistance and improves transistor performance. The conditioning permanent, while irradiation channel can produce transient effects. demonstrated lowers barrier at because thermally induced atom diffusion...
Device performance of solution-processed 2D semiconductors in printed electronics has been limited so far by structural defects and high interflake junction resistance. Covalently interconnected networks transition metal dichalcogenides potentially represent an efficient strategy to overcome both limitations simultaneously. Yet, the charge-transport properties such systems have not systematically researched. Here, mechanisms devices based on covalent MoS2 are unveiled via multiscale...
We report the fabrication and electrical characterization of germanium arsenide (GeAs) field-effect transistors with ultrathin channels. The transport is investigated in 20–280 K temperature range, revealing that p-type conductivity mobility are growing functions temperature. An unexpected peak observed dependence carrier density per area at ∼75 K. Such a feature explained considering increased concentration higher temperatures vertical band bending combined gate field lead to formation...
Abstract Monolayer molybdenum disulfide (MoS 2 ) nanosheets, obtained via chemical vapor deposition onto SiO /Si substrates, are exploited to fabricate field‐effect transistors with n‐type conduction, high on/off ratio, steep subthreshold slope, and good mobility. The transistor channel conductance increases the reducing air pressure due oxygen water desorption. Local field emission measurements from edges of MoS nanosheets performed in vacuum using a tip‐shaped anode. It is demonstrated...
Metal-insulator-semiconductor-insulator-metal (MISIM) heterostructures, with rectifying current-voltage characteristics and photosensitivity in the visible near-infrared spectra, are fabricated studied. It is shown that photocurrent can be enhanced by adding a multi-walled carbon nanotube film contact region to achieve responsivity higher than 100 mA W - 1 under incandescent light of 0.1 mW cm 2 . The optoelectrical MISIM heterostructures investigated at lower biases explained band...
Field emission from gallium oxide (β-Ga2O3) nanopillars, etched by Ne+ ion milling on β-polymorph (100) single crystals, is reported. A stable field current, with a record density over 100 A/cm2 and turn of ∼ 30 V/μm, achieved. We expect that the high enhancement factor about 200 at cathode-anode distance 1 μm can be further increased optimizing shape nanopillar apex. This work demonstrates material properties combined an appropriate nano-patterning make β-Ga2O3 competitive or better than...
We report a facile approach based on piezoelectric-driven nanotips inside scanning electron microscope to contact and electrically characterize ultrathin MoS2 (molybdenum disulfide) flakes SiO2/Si (silicon dioxide/silicon) substrate. apply such method analyze the electric transport field emission properties of chemical vapor deposition-synthesized monolayer MoS2, used as channel back-gate effect transistors. study effects gate-voltage range sweeping time current its hysteretic behavior....
There is controversy surrounding the moniker “high-entropy” materials due to unclear effect of entropy and enthalpy. The unique nanolayered structure MAX phases, with its structural covalent-metallic-covalent carbide interfaces, allowed us address this systematically. Here, we synthesized nearly 40 known novel phases containing 2 9 metals found that their enthalpic preference for short-range order remains until increases enough achieve all configurations transition in atomic planes. In...
MXenes are a promising class of 2D carbides and nitrides known for their high electrical conductivity, hydrophilicity, mechanical strength, unique optoelectronic properties, leading to numerous applications. However, scalable synthesis in 1D morphology, such as MXene nanotubes or scrolls, has not been demonstrated yet. This work presents versatile method manufacturing including Ti2CTx, Ti3C2Tx, Ti3CNTx, V2CTx, Nb2CTx, Ta4C3Tx. We demonstrate high-yield production up 45 wt% MAX phase...
Abstract MXenes represent one‐of‐a‐kind materials to devise radically novel technologies and achieve breakthroughs in optoelectronics. To exploit their full potential, precise control over the influence of stoichiometry on optical thermal properties, as well device performance, must be achieved. Here, characteristics optoelectronic devices based Ti 3 C 2 T x CT thin films are uncovered, highlighting striking difference photothermal responses laser irradiation under different experimental...
Nanostructured materials have wide potential applicability as field emitters due to their high aspect ratio. We hydrothermally synthesized MoS2 nanoflowers on copper foil and characterized emission properties, by applying a tip-anode configuration in which tungsten tip with curvature radius down 30-100 nm has been used the anode measure local properties from small areas 1-100 µm2. demonstrate that can be competitive other well-established emitters. Indeed, we show stable current measured...
PtS e 2 ultrathin films are used as the channel of back-gated field-effect transistors that investigated at different temperatures and under super-continuous white laser irradiation. The temperature-dependent behavior confirms semiconducting nature multilayer PtSe2, with p-type conduction, a hole mobility up to 40 cm2 V−1 s−1, significant gate modulation. Electrical conduction measured along directions shows isotropic transport. A reduction PtSe2 conductance is observed exposure light. Such...
Abstract InSb nanowire arrays with different geometrical parameters, diameter and pitch, are fabricated by a top‐down etching process on Si(100) substrates. Field emission properties of nanowires investigated using nano‐manipulated tip anode inside scanning electron microscope. Stable field current is reported, maximum intensity extracted from single 1 µA, corresponding to density as high 10 4 A cm −2 . Stability robustness the probed monitoring for about 3 h. By tuning cathode‐anode...