A5018182664- Graphene research and applications
- Semiconductor materials and interfaces
- Nanowire Synthesis and Applications
- Carbon Nanotubes in Composites
- Semiconductor materials and devices
- Silicon Nanostructures and Photoluminescence
- Photonic and Optical Devices
- Supercapacitor Materials and Fabrication
- Gas Sensing Nanomaterials and Sensors
- Quantum and electron transport phenomena
- Mechanical and Optical Resonators
- Quantum Dots Synthesis And Properties
- Advanced Memory and Neural Computing
- ZnO doping and properties
- Advancements in Semiconductor Devices and Circuit Design
- Surface and Thin Film Phenomena
University of Florida
2011-2017
Metal-semiconductor-metal (MSM) photodetectors based on graphene/p-type Si Schottky junctions are fabricated and characterized. Thermionic emission dominates the transport across above 260 K with a zero-bias barrier height of 0.48 eV. The reverse-bias dependence is found to result mostly from Fermi level shift in graphene. MSM exhibit responsivity 0.11 A/W normalized photocurrent-to-dark current ratio 4.55 × 104 mW−1, which larger than those previously obtained for similar detectors carbon...
Infrared, visible, and multispectral photodetectors are important components for sensing, security electronics applications. Current fabrication of these devices is based on inorganic materials grown by epitaxial techniques which not compatible with low‐cost large‐scale processing. Here, air‐stable solution‐processed double heterostructure photodetectors, using PbS quantum dots (QDs) as the photoactive layer, colloidal ZnO nanoparticles electron transport/hole blocking layer (ETL/HBL),...
We fabricate and study the ammonia sensing properties of graphitic nanoribbon films consisting multi-layer graphene nanoribbons. These show very good sensitivity to parts-per-million (ppm) level concentrations ammonia, which is further enhanced by platinum functionalization, resulting in a relative resistance response ∼70% when exposed 50 ppm ammonia. In addition, exhibits excellent repeatability full recovery air. also detail dependence on concentration temperature. find that shows...
Metal-semiconductor Schottky junction devices composed of chemical vapor deposition grown monolayer graphene on p-type silicon substrates are fabricated and characterized. Important diode parameters, such as the barrier height, ideality factor, series resistance, extracted from forward bias current-voltage characteristics using a previously established method modified to take into account interfacial native oxide layer present at graphene/silicon junction. It is found that factor can be...
The authors fabricate vertical geometry single-walled carbon nanotube (CNT) film/p-type silicon Schottky barrier photodetectors, where the CNT film acts as transparent metal and active semiconductor. experimentally characterize current-voltage, spectral responsivity, noise properties of these devices under reverse bias. find that film–Si photodetectors exhibit a large photocurrent-to-dark current ratio with responsivity high 0.10 A/W due to transmittance film. measured density shows 1/f...
Metal-oxide-semiconductor (MOS) devices with graphene as the metal gate electrode, silicon dioxide thicknesses ranging from 5 to 20 nm dielectric, and p-type semiconductor are fabricated characterized. It is found that Fowler-Nordheim (F-N) tunneling dominates current in these for oxide of 10 larger, whereas oxide, direct starts play a role determining total current. Furthermore, temperature dependences F-N characterized range 77–300 K. The coefficients effective barrier height extracted...
We fabricate, pattern, and analyze thin films composed of multilayer graphene nanoribbons. These are conductive at room temperature but depict noticeable insulating behavior low temperatures (<20 K) due to their disordered structure. study the transport in this strong localization regime by analyzing dependence resistivity on electric magnetic fields framework variable range hopping theory. Resistivity field confirms can be fitted effectively forward interference scattering wave function...
The electronic noise of single-walled carbon nanotube (CNT) film-Silicon Schottky junctions under forward bias is experimentally characterized. superposition a stable 1/f and temporally unstable Lorentzian observed, along with random telegraph signal (RTS) in the time domain. data analysis shows that results from RTS current fluctuations. agree well theoretical descriptions due to carrier trapping detrapping at interface states. Understanding properties CNT film-Si important for integration...
Graphene, which shows good electrical conductivity, high optical transparency, and mechanical flexibility, is a promising candidate for transparent, conductive, flexible electrodes in optoelectronic photovoltaic devices. Unlike conventional metal electrodes, graphene has the added advantage that its Fermi level hence workfunction can be tailored by chemical doping or electrostatic gating. As result, used traditional as well novel device structures. For purpose, integration of into...