A5025404135- Semiconductor Quantum Structures and Devices
- GaN-based semiconductor devices and materials
- Semiconductor materials and devices
- Nanowire Synthesis and Applications
- solar cell performance optimization
- Ferroelectric and Piezoelectric Materials
- Silicon and Solar Cell Technologies
- Advancements in Semiconductor Devices and Circuit Design
- Microwave Dielectric Ceramics Synthesis
- Silicon Nanostructures and Photoluminescence
- Photonic and Optical Devices
- Photovoltaic System Optimization Techniques
- Semiconductor materials and interfaces
- Nuclear Materials and Properties
- Chalcogenide Semiconductor Thin Films
- Electronic and Structural Properties of Oxides
- Quantum and electron transport phenomena
- Ion-surface interactions and analysis
- Fusion materials and technologies
- Advanced ceramic materials synthesis
University of Wisconsin–Madison
2018-2021
Texas A&M University
2017
Toyota Technological Institute
2014-2016
National Institute of Technology, Toyota College
2014
A multistep phase sequence following the crystallization of amorphous Al2O3 via solid-phase epitaxy (SPE) points to methods create low-defect-density thin films metastable cubic γ-Al2O3 polymorph. An film on a (0001) α-Al2O3 sapphire substrate initially transforms upon heating form epitaxial γ-Al2O3, followed by transformation monoclinic θ-Al2O3, and eventually α-Al2O3. Epitaxial layers with low mosaic widths in X-ray rocking curves can be formed SPE crystallizing from avoiding...
The growth of single crystals Ge-rich SiGe alloys in an extended composition range is demonstrated using the nanomembrane (NM) platform and III–V substrates. Thin films high-Ge-content are grown on GaAs(001) to below kinetic critical thickness released from substrate by selectively etching a release layer relax strain. resulting crystalline nanomembranes at natural lattice constant alloy transferred new host epitaxially overgrown similar compositions make thicker crystal. Straightforward...
The properties of the main acceptor state in GaAsN crystal grown by chemical beam epitaxy (CBE) are studied based on changes carrier concentration and temperature dependence junction capacitance due to annealing. p-type films shows a significant increase between 50 80 K energy level defect as-grown film was obtained at 0.161 eV above valence band maximum. This decreases its density increases with annealing time. Therefore, this is not thermally stable structure electrical change mainly...
Reconfiguration of amorphous complex oxides provides a readily controllable source stress that can be leveraged in nanoscale assembly to access broad range 3D geometries and hybrid materials. An SrTiO3 layer on Si:B/Si1-x Gex :B heterostructure is reconfigured at the atomic scale upon heating, exhibiting change volume ≈2% accompanying biaxial stress. The bilayer fabricated by molecular beam epitaxy, followed sputter deposition room temperature. processes yield oxide/semiconductor...
The hole traps associated with high background doping in p-type GaAsN grown by chemical beam epitaxy are studied based on the changes of carrier concentration, junction capacitance, and properties due to annealing. concentration was increased dramatically annealing time, capacitance–voltage (C–V) measurement. In addition, temperature dependence capacitance (C–T) rapidly two times. Such behavior is explained thermal ionization acceptor states. These acceptors main cause film, since estimated...
Material properties of chemical-beam-epitaxy-grown III–V-N materials have been studied extensively in the past few years as a candidate 1-eV junction multi-junction device. In this paper, we present theoretical modeling results to evaluate criteria how achieve high-efficiency solar cells using material. Then, will review and summarize recent research progress material within framework show these may be achieved.
We announced a open source solar cell modeling and analysis toolkit written in Python. The standard off-the-shelf simulation software is often difficult to modify or reuse some of its functionality into new models. In this package, we wrap the simulations individual modules application programming interfaces make them very user-friendly. This library contains wide range functions do heavy-lifting, error-prone jobs cells, such as unit conversions arithmetic operations spectrum data,...
The N-H related acceptor defects in p-type GaAsN grown by chemical beam epitaxy are studied deep level transient spectroscopy (DLTS). Two new signals appear DLTS spectra at 0.15 and 0.23 eV, when the crystals using deuterated As source (D-TDMAAs). This indicates that peaks originated from N-D defects. There two energy levels 0.11 0.19 which considered to play role of a double acceptor. difference between eV almost same, about 0.04 eV. Although these become deeper with increasing growth...
The formation mechanism of N-H related defects in GaAsN grown by chemical beam epitaxy is studied the isotope effects on local vibration modes (LVMs). When deuterated tris(dimethylamino)arsenic (TDMAAs) used as an arsenic source, new signals appear spectrum and they are attributed to N-D LVM signals. Therefore, As source molecule contributes GaAsN. TDMAAs flow rate increases, concentration at 2952cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...