Download or read book GaAs AlGaAs InGaP AlInP Material Systems for Quantum Well Infrared Photodetectors written by Nevenka Golubovic and published by . This book was released on 1994 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asymmetric Quantum Well Structures for Enhanced Infrared Photon Absorption written by Mehjabeen Akhtar Khan and published by . This book was released on 2013 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared to inter-band transition for photon absorption in a quantum wells, intra-band (or inter-subband) transitions in heterojunction (GaAs/InP) quantum wells can provide access to a broader range of wavelengths for detector design, specifically detectors operating in the mid infrared region of spectrum (4-12 [micro]m) and beyond is possible. These quantum wells not only provide great flexibility in optimizing the Eigen energy levels or wavefunctions, and inter-subband optical matrix elements determining the corresponding transition probability, but also allow controlling electron-phonon scattering rates and thus electron lifetime. The research presented in this dissertation investigates asymmetric quantum well structures formed through III-V semiconductor material system such as AlGaAs/ InxGa(1-x)As/InyGa(1-y) As/AlGaAs that can further improve the responsivity through higher carrier mobility. Asymmetry is introduced by using multiple materials to form the well region. The advantage of exploring stepped quantum well structure stems from experimental evidence that such structures are capable of absorbing normal incidence and thus eliminates the requirement of incorporating additional optical coupling schemes such as grating structures. An important contribution of this research is the development of an analytical model to analyze single or multiple quantum well structures to quantify photon absorption. The physical model developed in this work is based on non-equilibrium Green's function (NEGF), Fermi's golden rule and quantum mechanical wave impedance concept. The approach has two distinct advantages. First, it is accurate, easily programmable and yet computationally efficient. Second, it facilitates quantifying the broadening of states resulting from both photon absorption and tunneling, which provides important insight for improving detection efficiency. Instead of being presented through calculations, such broadening has been simply assumed in previously reported works. The method developed in this research provides an efficient methodology to quantify the absorption rate of photons with different polarizations. The study looks into the design and analysis of the wells to enhance infrared radiation detection, and suggests mechanisms to optimize the structures in terms of material choice, composition, structural geometry and applied voltages. The high electron mobility and hence drift velocity in InGaAs ( >5×106cm/s), along with low carrier recapture lifetime, is expected to improve the detection speed of the device. Unlike GaAs/AlGaAs, the lattice mismatch at InGaAs/AlGaAs interface is likely to introduce strain in the structure. The effect of such strain as well as the layer thickness is taken into account in this work. Also, a methodology for achieving voltage tenability, i.e. the ability to detect different wavelengths at different bias voltages has been investigated. Although both n-type and p-type systems have potential for optoelectronic devices, n-type quantum wells are more advantageous because of their nearly parabolic sub-band structure. As for material consideration, direct band gap material based systems, such as AlGaAs/InGaAs and AlGaAs/GaAs, have been found to be particularly suitable for n-type QWIP photodetectors. The reason being that the electrons in such materials occupy states around the [gamma]valley where the effective mass is smaller and therefore mobility is higher; a condition which leads to higher photoresponsivity. Moreover such systems allow the possibility of highly stable device operation owing to the insensitivity of intra-band transition energies to temperature fluctuation and reduced influence of Auger recombination.
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 Photodiodes written by Ilgu Yun and published by . This book was released on 2012 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book represents recent progress and development of the photodiodes including the fundamental reviews and the specific applications developed by the authors themselves. The key idea of this book is that it allows authors to deal with a wide range of backgrounds and research progresses in photodiode-related areas. With respect to the original collection of the book chapters, this book contains several improvements and new problems and related solutions are also discussed in the areas from fundamental physics and design to device and circuit applications. The book is intended for graduate students, engineers, and researchers who are especially interested in the area of optoelectronic device applications, including photodiodes, solar cells, CMOS image sensors, Optoelectronic Integrated Circuits, etc.
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1994 with total page 976 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compound Semiconductor Photonics written by Chua Soo-Jin and published by CRC Press. This book was released on 2020-03-26 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceeding is a collection of selected papers presented at Symposium O of Compound Semiconductor Photonics in the International Conference on Materials for Advanced Technology (ICMAT), which was held in Singapore from 28 June to 3 July 2009. The symposium covers a wide range of topics from fundamental semiconductor materials study to photonic device fabrication and application. The papers collected are of recent progress in the active and wide range of semiconductor photonics research. They include materials-related papers on III-As/P, III-nitride, quantum dot/wire/dash growth, ZnO, and chalcogenide, and devices-related papers on photonic crystals, VCSEL, quantum dot/dash lasers, LEDs, waveguides, solar cells and heterogeneous integrat
Download or read book Solar Cells written by Leonid A. Kosyachenko and published by BoD – Books on Demand. This book was released on 2015-10-22 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains chapters in which the problems of modern photovoltaics are considered. The majority of the chapters provide an overview of the results of research and development of different types of solar cells. Such chapters are completed by a justification for a new solar cell structure and technology. Of course, highly effective solar energy conversion is impossible without an in-depth examination of the solar cell components as physical materials. The relations between structural, thermodynamic, and optical properties of the physical material without addressing the band theory of solids are of both theoretical and practical interest. Requirements formulated for the material are also to be used for maximally efficient conversion of solar radiation into useful work.
Download or read book Metalorganic Vapor Phase Epitaxy MOVPE written by Stuart Irvine and published by John Wiley & Sons. This book was released on 2019-10-07 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Systematically discusses the growth method, material properties, and applications for key semiconductor materials MOVPE is a chemical vapor deposition technique that produces single or polycrystalline thin films. As one of the key epitaxial growth technologies, it produces layers that form the basis of many optoelectronic components including mobile phone components (GaAs), semiconductor lasers and LEDs (III-Vs, nitrides), optical communications (oxides), infrared detectors, photovoltaics (II-IV materials), etc. Featuring contributions by an international group of academics and industrialists, this book looks at the fundamentals of MOVPE and the key areas of equipment/safety, precursor chemicals, and growth monitoring. It covers the most important materials from III-V and II-VI compounds to quantum dots and nanowires, including sulfides and selenides and oxides/ceramics. Sections in every chapter of Metalorganic Vapor Phase Epitaxy (MOVPE): Growth, Materials Properties and Applications cover the growth of the particular materials system, the properties of the resultant material, and its applications. The book offers information on arsenides, phosphides, and antimonides; nitrides; lattice-mismatched growth; CdTe, MCT (mercury cadmium telluride); ZnO and related materials; equipment and safety; and more. It also offers a chapter that looks at the future of the technique. Covers, in order, the growth method, material properties, and applications for each material Includes chapters on the fundamentals of MOVPE and the key areas of equipment/safety, precursor chemicals, and growth monitoring Looks at important materials such as III-V and II-VI compounds, quantum dots, and nanowires Provides topical and wide-ranging coverage from well-known authors in the field Part of the Materials for Electronic and Optoelectronic Applications series Metalorganic Vapor Phase Epitaxy (MOVPE): Growth, Materials Properties and Applications is an excellent book for graduate students, researchers in academia and industry, as well as specialist courses at undergraduate/postgraduate level in the area of epitaxial growth (MOVPE/ MOCVD/ MBE).
Download or read book Theory of Graded Bandgap Thin Film Solar Cells written by Faiz Ahmad and published by Morgan & Claypool Publishers. This book was released on 2021-08-24 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin-film solar cells are cheap and easy to manufacture but require improvements as their efficiencies are low compared to that of the commercially dominant crystalline-silicon solar cells. An optoelectronic model is formulated and implemented along with the differential evolution algorithm to assess the efficacy of grading the bandgap of the CIGS, CZTSSe, and AlGaAs photon-absorbing layer for optimizing the power-conversion efficiency of thin-film CIGS, CZTSSe, and AlGaAs solar cells, respectively, in the two-terminal single-junction format. Each thin-film solar cell is modeled as a photonic device as well as an electronic device. Solar cells with two (or more) photon-absorbing layers can also be handled using the optolelectronic model, whose results will stimulate experimental techniques for bandgap grading to enable ubiquitous small-scale harnessing of solar energy.
Download or read book Clean Electricity From Photovoltaics written by Mary D Archer and published by World Scientific. This book was released on 2001-06-04 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic cells provide clean, reversible electrical power from the sun. Made from semiconductors, they are durable, silent in operation and free of polluting emissions. In this book, experts from all sectors of the PV community — materials scientists, physicists, production engineers, economists and environmentalists — give their critical appraisals of where the technology is now and what its prospects are./a
Download or read book Solar to Chemical Conversion written by Hongqi Sun and published by John Wiley & Sons. This book was released on 2021-04-29 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book systematically covers the fundamentals in solar energy conversion to chemicals, either fuels or chemical products. It includes natural photosynthesis with emphasis on artificial processes for solar energy conversion and utilization. The chemical processes of solar energy conversion via homogeneous and/or heterogeneous photocatalysis has been described with the mechanistic insights. It also consists of reaction systems toward a variety of applications, such as water splitting for hydrogen or oxygen evolution, photocatalytic CO2 reduction to fuels, and light driven N2 fixation, etc. This unique book offers the readers a broad view of solar energy utilization based on chemical processes and their perspectives for future sustainability.
Download or read book Semiconductor Electrodes written by Harry O. Finklea and published by Elsevier Publishing Company. This book was released on 1988 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductors have been studied as electrodes in electrochemical systems since the mid-1950's. However, it was not until the 1970's that the search for alternative energy sources, especially solar energy, led to an enormous expansion in semiconductor electrode research. One attractive option for solar energy conversion is the semiconductor liquid-junction solar cell, which can be designed to produce either electrical power or fuel such as hydrogen. Consequently the number of papers published concerning semiconductor electrodes has rapidly increased. Previous books have principally focused on the underlying theory (largely from solid state physics) and principles of operation of all semiconductor electrodes. It therefore seemed both useful and appropriate to review the field with the intention of collating information for each semiconductor or family of semiconductors, with contributions from authors who are all recognized experts in their field. Each chapter is devoted to critically assessing the recent literature on a particular semiconductor or family of semiconductors.
Download or read book The Physics Of Solar Cells written by Jenny A Nelson and published by World Scientific Publishing Company. This book was released on 2003-05-09 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive introduction to the physics of the photovoltaic cell. It is suitable for undergraduates, graduate students, and researchers new to the field. It covers: basic physics of semiconductors in photovoltaic devices; physical models of solar cell operation; characteristics and design of common types of solar cell; and approaches to increasing solar cell efficiency. The text explains the terms and concepts of solar cell device physics and shows the reader how to formulate and solve relevant physical problems. Exercises and worked solutions are included.
Download or read book Modelling Photovoltaic Systems Using PSpice written by Luis Castañer and published by John Wiley & Sons. This book was released on 2003-03-07 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaics, the direct conversion of light from the sun into electricity, is an increasingly important means of distributed power generation. The SPICE modelling tool is typically used in the development of electrical and electronic circuits. When applied to the modelling of PV systems it provides a means of understanding and evaluating the performance of solar cells and systems. The majority of books currently on the market are based around discussion of the solar cell as semiconductor devices rather than as a system to be modelled and applied to real-world problems. Castaner and Silvestre provide a comprehensive treatment of PV system technology analysis. Using SPICE, the tool of choice for circuits and electronics designers, this book highlights the increasing importance of modelling techniques in the quantitative analysis of PV systems. This unique treatment presents both students and professional engineers, with the means to understand, evaluate and develop their own PV modules and systems. * Provides a unique, self-contained, guide to the modelling and design of PV systems * Presents a practical, application oriented approach to PV technology, something that is missing from the current literature * Uses the widely known SPICE circuit-modelling tool to analyse and simulate the performance of PV modules for the first time * Written by respected and well-known academics in the field
Download or read book High Efficient Low Cost Photovoltaics written by Vesselinka Petrova-Koch and published by Springer Science & Business Media. This book was released on 2009 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: A bird's-eye view of the developmental trends and problems of recent photovoltaics is presented. The worldwide effort to develop high-efficiency low-cost PV modules, making use of most efficient solar cells and clever low-cost solar concentrators is described.
Download or read book Semiconductor Radiation Detectors written by Alan Owens and published by CRC Press. This book was released on 2019-05-31 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: Choice Recommended Title, July 2020 Bringing together material scattered across many disciplines, Semiconductor Radiation Detectors provides readers with a consolidated source of information on the properties of a wide range of semiconductors; their growth, characterization and the fabrication of radiation sensors with emphasis on the X- and gamma-ray regimes. It explores the promise and limitations of both the traditional and new generation of semiconductors and discusses where the future in semiconductor development and radiation detection may lie. The purpose of this book is two-fold; firstly to serve as a text book for those new to the field of semiconductors and radiation detection and measurement, and secondly as a reference book for established researchers working in related disciplines within physics and engineering. Features: The only comprehensive book covering this topic Fully up-to-date with new developments in the field Provides a wide-ranging source of further reference material
Download or read book Molecular Beam Epitaxy written by John Wilfred Orton and published by . This book was released on 2015 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a history of Molecular Beam Epitaxy (MBE) as applied to the growth of semiconductor thin films (note that it does not cover the subject of metal thin films). It begins by examining the origins of MBE, first of all looking at the nature of molecular beams and considering their application to fundamental physics, to the development of nuclear magnetic resonance and to the invention of the microwave MASER. It shows how molecular beams of silane (SiH4) were used to study the nucleation of silicon films on a silicon substrate and how such studies were extended to compound semiconductors such as GaAs. From such surface studies in ultra-high vacuum the technique developed into a method of growing high quality single crystal films of a wide range of semiconductors. Comparing this with earlier evaporation methods of deposition and with other epitaxial deposition methods such as liquid phase and vapour phase epitaxy (LPE and VPE). The text describes the development of MBE machines from the early 'home-made' variety to that of commercial equipment and show how MBE was gradually refined to produce high quality films with atomic dimensions. This was much aided by the use of various in-situ surface analysis techniques, such as reflection high energy electron diffraction (RHEED) and mass spectrometry, a feature unique to MBE. It looks at various modified versions of the basic MBE process, then proceed to describe their application to the growth of so-called 'low-dimensional structures' (LDS) based on ultra-thin heterostructure films with thickness of order a few molecular monolayers. Further chapters cover the growth of a wide range of different compounds and describe their application to fundamental physics and to the fabrication of electronic and opto-electronic devices. The authors study the historical development of all these aspects and emphasise both the (often unexpected) manner of their discovery and development and the unique features which MBE brings to the growth of extremely complex structures with monolayer accuracy.
