Download or read book Type II Gallium Antimonide Quantum Dots in Gallium Arsenide Single Junction Solar Cells written by Abu Syed Mahajumi and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bandstructure Engineering of Indium Arsenide Quantum Dots in Gallium Arsenide Antimonide Barriers for Photovoltaic Applications written by Jonathan Boyle and published by ProQuest. This book was released on 2008 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing the efficiency of solar cell technology is one of the current research aims being under taken in order to help supply growing global energy demands. The research presented in this thesis contributes to the current materials hunt for suitable candidates for an Intermediate Band Solar Cell (IBSC). A background on other "third generation" photovoltaic concepts along with details about the IBSC concept is also presented.
Download or read book Indium Arsenide gallium Arsenide Antimonide Quantum Dots and Their Applications in Intermediate Band Solar Cells written by Anthony James Meleco and published by . This book was released on 2016 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Indium Gallium arsenide Quantum Dot Materials for Solar Cell Applications written by Anup Pancholi and published by ProQuest. This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The last few years have seen rapid advances in nanoscience and nanotechnology, allowing unprecedented manipulation of nanostructures controlling solar energy capture, conversion, and storage. Quantum confined nanostructures, such as quantum wells (QWs) and quantum dots (QDs) have been projected as potential candidates for the implementation of some high efficiency photovoltaic device concepts, including the intermediate band solar cell (IBSC). In this dissertation research, we investigated multiple inter-related themes, with the main objective of providing a deeper understanding of the physical and optical properties of QD structures relevant to the IBSC concept. These themes are: (i) Quantum engineering and control of energy levels in QDs, via a detailed study of the electronic coupling in multilayer QD structures; (ii) Controlled synthesis of well-organized, good quality, high volume density, and uniform-size QD arrays, in order to maximize the absorption efficiency and to ensure the coupling between the dots and the formation of the minibands; and (iii) Characterization of carrier dynamics and development of techniques to enhance the charge transport and efficient light harvesting. A major issue in a QD-based IBSC is the occurrence of charge trapping, followed by recombination in the dots, which results in fewer carriers being collected and hence low quantum efficiency. In order to collect most of the light-generated carriers, long radiative lifetimes, higher mobilities, and a lower probability of non-radiative recombination events in the solar cell would be desirable. QD size-dependent radiative lifetime and electronic coupling in multilayer QD structures were studied using photoluminescence (PL) and time-resolved photoluminescence (TRPL). For the uncoupled QD structures with thick barriers between the adjacent QD layers, the radiative lifetime was found to increase with the QD size, which was attributed to increased oscillator strength in smaller size dots. On the other hand, in the sample with thin barrier and electronically coupled QDs, the radiative lifetime increases and later decreases with the dot size. This is due to the enhancement of the oscillator strength in the larger size, coherently coupled QDs. In order to improve the quality of multi-layer QD structures, strain compensated barriers were introduced between the QD layers grown on off-oriented GaAs (311)B substrate. The QD shape anisotropy resulted from the growth on off-oriented substrate was studied using polarization-dependent PL measurements both on the surface and the edge of the samples. The transverse electric mode of the edge-emitted PL showed about 5° deviation from the sample surface for the dots grown on (311)B GaAs, which was attributed to the tilted vertical alignment and the shape asymmetry of dots resulted from the substrate orientation. Significant structural quality improvements were attained by introducing strain compensated barriers, i.e., reduction of misfit dislocations and uniform dot size formation. Longer lifetime (~1 ns) and enhanced PL intensity at room temperature were obtained, compared to those in conventional multilayer (In, Ga)As/GaAs QD structures. A significant increase in the open circuit voltage (V oc) was observed for the solar cell devices fabricated with the strain compensated structures. A major issue in a QD IBSC is the occurrence of charge trapping, followed by recombination in the dots, which results in fewer carriers being collected, and hence low quantum efficiency. We proposed and studied a novel structure, in which InAs QDs were sandwiched between GaAsSb (12% Sb) strain-reducing layers (SRLs) with various thicknesses. Both short (~1 ns) and long (~4-6 ns) radiative lifetimes were measured in the dots and were attributed to type-I and type-II transitions, respectively, which were induced by the band alignment modifications at the QD/barrier interface in the structures analyzed, due to the quantum confinement effect resulting from different GaAsSb barrier thicknesses. Based on our findings, a structure with type-II QD/barrier interface with relatively long radiative recombination lifetime may be a viable candidate in designing IBSC.
Download or read book GaAs Solar Cell Radiation Handbook written by B. E. Anspaugh and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gallium Arsenide based Ternary Compounds and Multi band gap Solar Cell Research written by and published by . This book was released on 1993 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.
Download or read book Gallium Arsenide Thin Films on Tungsten graphite Substrates written by Southern Methodist University and published by . This book was released on 1978 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gallium Arsenide Solar Cells on Single Crystalline Silicon Substrates written by Hossein Firouzi and published by . This book was released on 1986 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Degradation Studies of N type Gallium Arsenide Electrodes in Liquid Junction Solar Cells written by Michael Allan Purcell and published by . This book was released on 1982 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Power Generation and the Environment written by Anco S. Blazev and published by CRC Press. This book was released on 2021-01-07 with total page 1333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural and man-made changes in the environment create a very complex picture. This book analyzes this picture and provides snapshots of different areas of interest and to make suggestions for future work on cleaning and stabilizing the Earth's environment. Starting with conventional energy generation and moving on to renewable energies, this book analyzes and calculates their environmental impact and the lesser known aspects of their "cradle-to-grave" life cycle such as the irreversible environmental damage done during the manufacturing of solar and wind equipment and during the installation, operation, and decommissioning of large scale hydro, solar, and wind power plants.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2002 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Power Generation written by P. Jayarama Reddy and published by CRC Press. This book was released on 2012-03-22 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a global perspective of the current state of affairs in the field of solar power engineering. In four parts, this well-researched volume informs about: Established solar PV (photovoltaic) technologies Third-generation PV technologies based on new materials with potential for low-cost large-scale production Solar cell technology based on new (third-generation) concepts, such as quantum dot solar cells and nano wire solar cells using silicon and compound semiconductors Economic implications and effects, as well as policies and incentives in various countries of the world involved with solar energy implementation In addition to discussing manufacturing facts and implementation issues, this book emphasizes the implications of policy measures in countries with good PV activity, such as Japan, China, India, Germany, Spain, France, Italy, the United States, and Canada. This volume is intended as a reference for a global audience of advanced students and R&D and industry professionals, as well as investors and policy-makers with fundamental knowledge of photovoltaic technology.
Download or read book Organic Solar Cells written by Pankaj Kumar and published by CRC Press. This book was released on 2016-10-03 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains detailed information on the types, structure, fabrication, and characterization of organic solar cells (OSCs). It discusses processes to improve efficiencies and the prevention of degradation in OSCs. It compares the cost-effectiveness of OSCs to those based on crystalline silicon and discusses ways to make OSCs more economical. This book provides a practical guide for the fabrication, processing, and characterization of OSCs and paves the way for further development in OSC technology.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gallium Arsenide Solar Cells written by Sanford Sillman and published by . This book was released on 1976 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book GALLIUM ARSENIDE SOLAR CELLS Second Phase Final Report written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gallium Arsenide Solar Cells written by J. W. Burgess and published by . This book was released on 1982 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
