A5085883425- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Ga2O3 and related materials
- Silicon Carbide Semiconductor Technologies
- Physics of Superconductivity and Magnetism
- Organometallic Compounds Synthesis and Characterization
- Semiconductor Quantum Structures and Devices
- Semiconductor materials and interfaces
- Iron-based superconductors research
- Superconductivity in MgB2 and Alloys
- Agricultural Science and Fertilization
- Rare-earth and actinide compounds
- Metal complexes synthesis and properties
- Advancements in Semiconductor Devices and Circuit Design
- Thermal and Kinetic Analysis
- TiO2 Photocatalysis and Solar Cells
- Plant Micronutrient Interactions and Effects
- Transition Metal Oxide Nanomaterials
- Magnetic properties of thin films
- Analytical Chemistry and Sensors
- ZnO doping and properties
- Advanced Photocatalysis Techniques
- Magnetic and transport properties of perovskites and related materials
- Catalytic Processes in Materials Science
- Gas Sensing Nanomaterials and Sensors
University of Padua
2021-2022
Solid State Physics Laboratory
2015-2020
Indian Institute of Technology Delhi
2017-2020
National Yang Ming Chiao Tung University
2020
CSIR National Physical Laboratory of India
1983-2019
National Institute Of Technology Silchar
2011
National Physical Laboratory
1981-2006
The effects of γ-ray irradiation on AlGaN/GaN epitaxial layers and high electron mobility transistor (HEMT) devices have been systematically investigated. layer structure HEMT device has irradiated cumulatively with dose the order 16 kGy. x-ray diffraction (XRD) analysis sample shows a lowering in full width at half maximum (FWHM) values along (102) (002) planes comparison to pristine due partial annealing effect. A decrease in-plane biaxial stress from 1.20 GPa 0.75 observed. Raman spectrum...
This paper presents the electrical comparison of Au and Ni/Au gated HEMT devices diodes. Schottky diodes on an AlGaN/GaN heterostructure exhibit better performance in to conventional with improved barrier height (SBH) lower reverse leakage current. The SBH extracted from I-V for is 1.29 eV 0.74 eV, respectively. contacts GaN have a ideality factor 1.55 than Ni, which 1.61. Capacitance-voltage measurement revealed positive shift threshold voltage case reduced capacitance value respect...
This article reports an experimental approach to analyze the kink effect phenomenon which is usually observed during GaN high electron mobility transistor (HEMT) operation. De-trapping of charge carriers one prominent reasons behind effect. The commonly non-monotonic behavior pattern analyzed under two different device operating conditions and it found that de-trapping mechanisms are responsible for a particular behavior. These investigated through time delay analysis shows presence traps...
In this article, we demonstrate that a physics-based compact model can facilitate to analyze the reliability using an example of γ-ray induced instability in AlGaN/GaN HEMTs. First, typical HEMTs are subjected cumulative y-ray irradiation, exhibiting drain current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> ) increase. order further elucidation, root cause, is implemented and calibrated with pristine case. Then, I -V...
Double-Gate MOSFET (DGFET) is one of the promising technologies for sub-50 nm transistor design. To accommodate future technology nodes, dimensions have to be reduced which leads several disadvantages in function. By using double-gate transistors many these problems can resolved give efficient circuit performance. As we go further scaling down, use logic gate design gives significant improvements over conventional single-gate CMOS These are observed by comparing designs a full-adder with and...
This paper presents results concerning the dynamic performance and reliability of Fe-doped C-doped 0.15-μm gate AlGaN/GaN HEMTs. Step-stress tests at increasing drain-source voltage different gate-source voltages are specifically reported. HEMTs exhibit, under both off- on-state conditions, excellent parametric stability up to breakdown. devices instead affected by enhanced degradation effects during step stress experiments compared ones, consisting R<sub>ON</sub> increase off-state...
Cumulative dose gamma radiation effects on current-voltage characteristics of GaN Schottky diodes have been investigated. The different area fabricated AlGaN/GaN high electron mobility transistor (HEMT) epi-layer structure grown over SiC substrate and irradiated with a up to the order 104 Gray (Gy). Post irradiation characterization shows shift in turn-on voltage improvement reverse leakage current. Other calculated parameters include barrier height, ideality factor saturation height has...
Abstract This article reports the effect of gamma ( γ )-ray irradiation on barrier inhomogeneities that leads towards improvement in diode parameters Ni-AlGaN/GaN Schottky diodes. The diodes were subjected to a cumulative -ray dose up 15 kGy and their current–voltage I – V ) capacitance–voltage C characteristics measured simultaneously at different temperatures during pristine stage after each radiation dose. height Φ b had an increase 10% 20% temperature range greater than 250 K. Whereas,...
Several mechanisms may contribute to the degradation of GaN transistors; in this paper we discuss main processes that limit lifetime power devices, with focus on following relevant aspects: (i) degradation/breakdown induced by off-state bias; (ii) origin vertical leakage and breakdown; (iii) failure gate stack MIS-HEMTs transistors p-type gate. The data reviewed help reader understanding issues related development GaN-based transistors, give hints possible strategies improve device...
Abstract A micro-optic switch based on total-internal reflection using ferroelectric liquid crystal is described. It uses a chiral nematic (N*)-smectic C* phase transition (FLC) in which the optic axis rotates by 90° during switching. The device exploits maximum of birefringence minimizing its size. material inherent advantage tilt angle stability with temperature provides switching characteristics are more stable over wide range temperature. An exceptionally high attenuation 5x107 off state...
The lead doped Bi based copper oxide high-Tc superconductors with different nominal compositions and annealing time periods are studied. highest Tc (zero) achieved is 112 K in bulk phase 2223. varying intensity of the low angle line at 2θ ≈ 4.7° suggests gradual formation due to long nearly 200 250 h. It also found that starts degrading after h reduces. distortion 2223 suggested by broadening XRD peaks, SEM studies support above contention. EDAX show no presence Pb crystallites. Es werden...
TiO2 has been used for gas sensing devices [1] photo catalytic [2] and photoelectric [3]. Recently the dielectric properties of have great interest applications in telecommunications industry due to its unusual high constant low loss. The use layers materials small scale metal insulator semiconductor considered numerous recent publications these unable maintain same capacitance density as SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML"...