A5010909815- Semiconductor Quantum Structures and Devices
- solar cell performance optimization
- Chalcogenide Semiconductor Thin Films
- Energy Harvesting in Wireless Networks
- Innovative Energy Harvesting Technologies
- Advanced Semiconductor Detectors and Materials
- Quantum Dots Synthesis And Properties
- Nanowire Synthesis and Applications
- GaN-based semiconductor devices and materials
- Perovskite Materials and Applications
- Advancements in Semiconductor Devices and Circuit Design
- Photovoltaic System Optimization Techniques
- Semiconductor materials and interfaces
- Cloud Computing and Resource Management
- Electrowetting and Microfluidic Technologies
- Semiconductor Lasers and Optical Devices
Boston University
2020
University of Michigan
2012-2017
University of Illinois Urbana-Champaign
2014
University of California, Santa Barbara
2014
Indoor photovoltaic energy harvesting is a promising candidate to power millimeter (mm)-scale systems. The theoretical efficiency and electrical performance of photovoltaics under typical indoor lighting conditions are analyzed. Commercial crystalline Si fabricated GaAs Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.2</sub> Ga xmlns:xlink="http://www.w3.org/1999/xlink">0.8</sub> As cells were experimentally measured simulated AM 1.5 solar...
GaAs photovoltaics are promising candidates for indoor energy harvesting to power small-scale ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\approx 1$ </tex-math></inline-formula> mm <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) electronics. This application has stringent requirements on dark current, recombination, and shunt leakage paths due low-light conditions small device dimensions....
Energy harvesting is an attractive solution to extend system lifetime for internet of everything (IoE) nodes. Ambient light a common energy source that can be harvested by photovoltaic (PV) cells. However, intensity varies widely depending on location, ranging from ~10s lux in dim indoor conditions ~100klux under direct sunlight. Designing fully integrated harvester spans such wide range with high efficiency challenging, especially since typically low PV cell voltage requires upconversion...
Quantum dots can provide electronic states that act as ``stepping stones'' in absorbing light, thereby improving the efficiency of solar cells. The authors identify a transition temperature at which significant gain energy absorption is seen GaSb/GaAs quantum dots, and show this due to particular alignment bands underlying structure. Related behaviors could also be valuable optoelectronics information processing.
In this work, we study type-II GaSb/GaAs quantum-dot intermediate band solar cells (IBSCs) by means of quantum efficiency (QE) measurements. We are able, for the first time, to measure an absolute QE which clearly reveals three characteristic bandgaps IBSC; E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> , xmlns:xlink="http://www.w3.org/1999/xlink">H</sub> and xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> found values 1.52, 1.02,...
ZnTe doped with high concentrations of oxygen has been proposed in previous works as an intermediate band (IB) material for photovoltaic applications. The existence extra optical transitions related to the presence IB already demonstrated this and it possible measure absorption coefficient from valence (VB) IB. In study, we present first measurement associated conduction (CB) ZnTeO. samples used are 4-μm-thick layers or without O a concentration ~10 <sup...
Low power electronic circuitry, including wirelessly interconnected sensor nodes, is a transformational technology that can be applied to broad range of applications. These low systems still require electrical power, ideally from ambient energy sources. Ambient sources light provide sufficient for these Stray sunlight more than adequate, though it not available in all locations. Indoor lighting may also source, the characteristics spectrum are significantly different solar spectrum, where...
Limitations on the open-circuit voltage of p-ZnTe/n-ZnSe heterojunction solar cells are studied via current-voltage (I-V) measurements under concentration and at variable temperature. The reaches a maximum value 1.95 V 77 K 199 suns. shows good agreement with calculated built-in potential 2.00 K. These results suggest that is limited by band offsets associated type-II lineup, rather than bandgap energy ZnTe absorber material.
The increasing demand for miniature autonomous sensors requires low cost integration methods, but to date, material limitations have prevented the direct growth of optically active III-V materials on CMOS devices. We report deposition GaAs nanowires polycrystalline conductive films allow optoelectronic devices dissimilar materials. Undoped, Si-doped, and Be-doped were grown at Ts = 400 °C oxide (indium tin oxide) metallic (platinum titanium) films. Be-doping is shown significantly reduce...
Energy conversion in solar cells incorporating ZnTeO base layers is presented. The incorporate intermediate electronic states located approximately 0.4eV below the conduction band edge as a result of substitution O Te sites ZnTe lattice. Cells with demonstrate optical response at energies lower than bandedge, feature that absent reference layers. Quantum efficiency significantly improved incorporation ZnSe emitter/window and transition from growth on GaAs substrates to GaSb near lattice match ZnTe.
ZnTe doped with high concentrations of oxygen has been proposed in previous works as intermediate band (IB) material for photovoltaic applications. The existence extra optical transitions related to the presence an IB already demonstrated this and it possible measure absorption coefficient from valence (VB) IB. In work we present first measurement associated conduction (CB) ZnTe:O.
ZnTe doped with high concentrations of oxygen has been proposed in previous works as intermediate band (IB) material for photovoltaic applications. The existence extra optical transitions related to the presence an IB already demonstrated this and it possible measure absorption coefficient from valence (VB) IB. In work we present first measurement associated conduction (CB) ZnTe:O.
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