Download or read book Optical Properties of Ultra thin Layers in III V Semiconductors written by Andreas Joachim Bitz and published by . This book was released on 1998 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optical Properties of III V Semiconductors written by Heinz Kalt and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is concerned with the III-V bulk and low-dimensional semiconductors, with the emphasis on the implications of multi-valley bandstructures for the physical mechanisms essential for opto-electronic devices. The optical response of such semiconductor materials is determined by many-body effects such as screening, gap narrowing, Fermi-edge singularity, electron-hole plasma and liquid formation. Consequently, the discussion of these features reflects such interdependencies with the dynamics of excitons and carriers resulting from intervalley coupling.

Download or read book Optical Properties of III V Semiconductors written by Scott Robert Kisting and published by . This book was released on 1991 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: A GaAs-Al$sb{0.22}$Ga$sb{0.78}$As heterostructure was prepared and used as a multimode optical waveguide in order to measure the sub bandgap energy- and temperature-dependent refractive index of GaAs. Propagation constants for the individual modes were measured by exciting one mode at a time using a real-space diffraction grating coupler. The resulting eigenmode distributions were used to obtain the refractive index of GaAs at a matrix of sub bandgap photon energies (1.40 eV $

Download or read book Characterization of the Structural and Optical Properties of III V Semiconductor Materials for Solar Cell Applications written by Hongen Xie and published by . This book was released on 2016 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work contained in this dissertation is focused on the structural and optical properties of III-V semiconductor structures for solar cell applications. By using transmission electron microscopy, many of their structural properties have been investigated, including morphology, defects, and strain relaxation. The optical properties of the semiconductor structures have been studied by photoluminescence and cathodoluminescence.Part of this work is focused on InAs quantum dots (QDs) embedded in AlGaAs matrices. This QD system is important for the realization of intermediate-band solar cells, which has three light absorption paths for high efficiency photovoltaics. The suppression of plastic strain relaxation in the QDs shows a significant improvement of the optoelectronic properties. A partial capping followed by a thermal annealing step is used to achieve spool-shaped QDs with a uniform height following the thickness of the capping layer. This step keeps the height of the QDs below a critical value that is required for plastic relaxation. The spool-shaped QDs exhibit two photoluminescence peaks that are attributed to ground and excited state transitions. The luminescence peak width is associated with the QD diameter distribution. An InAs cover layer formed during annealing is found responsible for the loss of the confinement of the excited states in smaller QDs. The second part of this work is focused on the investigation of the InxGa1-xN thin films having different bandgaps for double-junction solar cells. InxGa1-xN films with x 0.15 were grown by metal organic chemical vapor deposition. The defects in films with different indium contents have been studied. Their effect on the optical properties of the film have been investigated by cathodoluminescence. InxGa1-xN films with indium contents higher than 20% were grown by molecular beam epitaxy. The strain relaxation in the films has been measured from electron diffraction patterns taken in cross-sectional TEM specimens. Moiré fringes in some of the films reveal interfacial strain relaxation that is explained by a critical thickness model.

Download or read book Optical Properties and Applications of Semiconductors written by Inamuddin and published by CRC Press. This book was released on 2022-07-18 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductors with optical characteristics have found widespread use in evolving semiconductor photovoltaics, where optical features are important. The industrialization of semiconductors and their allied applications have paved the way for optical measurement techniques to be used in new ways. Due to their unique properties, semiconductors are key components in the daily employed technologies in healthcare, computing, communications, green energy, and a range of other uses. This book examines the fundamental optical properties and applications of semiconductors. It summarizes the information as well as the optical characteristics and applicability of semiconductors through an in-depth review of the literature. Accomplished experts in the field share their knowledge and examine new developments. FEATURES Comprehensive coverage of all types of optical applications using semiconductors Explores relevant composite materials and devices for each application Addresses the optical properties of crystalline and amorphous semiconductors Describes new developments in the field and future potential applications Optical Properties and Applications of Semiconductors is a comprehensive reference and an invaluable resource for engineers, scientists, academics, and industry R&D teams working in applied physics.

Download or read book III Nitride Semiconductors written by Hongxing Jiang and published by CRC Press. This book was released on 2002-06-28 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first part of a comprehensive overview of fundamental optical properties of III-nitride semiconductors. All optoelectronic applications based on III-nitrides are due to their unique optical properties and characterizations of III-nitrides. Much information, which is critical to the design and improvement of optoelectronic devices based on III-nitrides has been obtained in the last several years. This is the first of a two part Volume in the series Optoelectronic Properties of Semiconductors and Superlattices. Part I begins with time-resolved studies of semiconductors and moves on to the emphasis on time-resolved photoluminescence of nitride materials and device technology and focuses on Raman studies and properties of III Nitrides. This unique volume provides a comprehensive review and introduction of the defects and structural properties of GaN and related compounds. This would be excellent for newcomers to the field and is a stimulus to further advances for experienced researchers.III-Nitride Semiconductors: Optical Properties Part I combines contributions from active experts in the field with diverse backgrounds. This book provides a very important step in advancing the state of research and device development in the field of III-nitride materials.

Download or read book Optical Properties of Semiconductors written by G. Martinez and published by Springer Science & Business Media. This book was released on 1992-11-30 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is widely recognized that an understanding of the optical pro perties of matter will give a great deal of important information re levant to the fundamental physical properties. This is especially true in semiconductor physics for which, due to the intrinsic low screening of these materials, the optical response is quite rich. Their spectra reflect indeed as well electronic as spin or phonon transitions. This is also in the semiconductor field that artificial structures have been recently developed, showing for the first time specific physical properties related to the low dimentionality of the electronic and vi bronic properties : with this respect the quantum and fractional quan tum Hall effects are among the most well known aspects. The associated reduced screening is also a clear manifestation of these aspects and as such favors new optical properties or at least significantly enhan ces some of them. For all these reasons, it appeared necessary to try to review in a global way what the optical investigation has brought today about the understanding of the physics of semiconductors. This volume collects the papers presented at the NATO Advanced study Inst i tut e on "Optical Properties of Semiconductors" held at the Ettore Majorana Centre, Erice, Sicily on March 9th to 20th, 1992. This school brought together 70 scientists active in research related to optical properties of semiconductors. There were 12 lecturers who pro vided the main contributions .

Download or read book Optical Properties of Thin Semiconductor Device Structures with Reflective Back surface Layers written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrathin semiconductor device structures incorporating reflective internal or back surface layers have been investigated recently as a means of improving photon recuperation, eliminating losses associated with free carrier absorption in conductive substrates and increasing the above bandgap optical thickness of thermophotovoltaic device structures. However, optical losses in the form of resonance absorptions in these ultrathin devices have been observed. This behavior in cells incorporating epitaxially grown FeAl layers and in devices that lack a substrate but have a back-surface reflector (BSR) at the rear of the active layers has been studied experimentally and modeled effectively. For thermophotovoltaic devices, these resonances represent a significant loss mechanism since the wavelengths at which they occur are defined by the active TPV cell thickness of (approximately) 2--5 microns and are in a spectral range of significant energy content for thermal radiators. This study demonstrates that ultrathin semiconductor structures that are clad by such highly reflective layers or by films with largely different indices of refraction display resonance absorptions that can only be overcome through the implementation of some external spectral control strategy. Effective broadband, below-bandgap spectral control using a back-surface reflector is only achievable using a large separation between the TPV active layers and the back-surface reflector.

Download or read book Optical properties of organic semiconductors From sub monolayers to crystalline films written by and published by Cuvillier Verlag. This book was released on 2006-05-10 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have measured the optical properties of films of the organic semiconductors PTCDA and HBC, prepared by Organic Molecular Beam Expitaxy (OMBE), on different substrates by means of Differential Reflectance Spectroscopy (DRS). The optical setup used [51] allows to characterize the samples in situ and during the film growth. This enables us to directly follow the thickness dependent optical properties of the organic films, starting from submonolayer coverage up to thicker films on the order of 20 monolayers (ML) film thickness. However, due to the different optical nature of the different substrates used, i.e., mica, glass, Au(111), and HOPG, the DRS signal can not directly be interpreted in terms of the absorption of the films. Rather, the optical constants n (index of refraction) and k (absorption index) of the organic films have to be calculated to be able to discuss the spectral absorption of the films. We have proposed a method by which the calculation of the optical constants of thin films on arbitrary substrates from just one spectral measurement (in our case the DRS) becomes possible. The results fulfill a priori a Kramers-Kronig consistency, characteristic for physically meaningful values of the optical constants, and no specific model is needed to express the spectral behavior of the optical constants. Still, the requirement that the absorption index has to approach zero sufficiently at the measurement intervals restricts the application of our method to a class of materials, which exhibit distinct and well-separated absorption bands, like e.g. organic semiconductors. By means of appropriate extrapolation procedures, the method is able to account for small non-zero values of the absorption index at the boundaries of the measurement interval. Although we exclusively discussed the application of our method to differential reflectance spectra, it is anticipated that it works for all other optical quantities likewise.

Download or read book Effect of Nanoscale Defects on Electrical and Optical Properties in III V Semiconductors written by Jeong Ho You and published by ProQuest. This book was released on 2007 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most epitaxially grown semiconductor layers contain dislocations due to mismatch of lattice parameters and thermal expansion coefficients with those of the substrate. Gallium nitride in particular, which has wide applications in blue light-emitting diodes, blue lasers, and high-power transistors, contains extremely high dislocation densities due to the lack of lattice-matched substrates. In this dissertation, effects of edge and screw dislocations on electrical and optical properties in GaN are presented and compared with GaAs.

Download or read book Optical Properties of III V Semiconductors written by Heinz Kalt and published by . This book was released on 1992 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectroscopy of Semiconductor Microstructures written by Gerhard Fasol and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 661 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a NATO ARW held in Venice, Italy, May 9-13, 1989

Download or read book III V Compound Semiconductors and Devices written by Keh Yung Cheng and published by Springer Nature. This book was released on 2020-11-08 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook gives a complete and fundamental introduction to the properties of III-V compound semiconductor devices, highlighting the theoretical and practical aspects of their device physics. Beginning with an introduction to the basics of semiconductor physics, it presents an overview of the physics and preparation of compound semiconductor materials, as well as a detailed look at the electrical and optical properties of compound semiconductor heterostructures. The book concludes with chapters dedicated to a number of heterostructure electronic and photonic devices, including the high-electron-mobility transistor, the heterojunction bipolar transistor, lasers, unipolar photonic devices, and integrated optoelectronic devices. Featuring chapter-end problems, suggested references for further reading, as well as clear, didactic schematics accompanied by six information-rich appendices, this textbook is ideal for graduate students in the areas of semiconductor physics or electrical engineering. In addition, up-to-date results from published research make this textbook especially well-suited as a self-study and reference guide for engineers and researchers in related industries.

Download or read book Low Dimensional Structures in Semiconductors written by A.R. Peaker and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a sequence of reviews presented at the NATO Advanced Study Institute on 'Low Dimensional Structures in Semiconductors ... from Basic Physics to Applications.' This was part of the International School of Materials Science and 1990 at the Ettore Majorana Centre in Sicily. Technology held in July Only a few years ago, Low Dimensional Structures was an esoteric concept, but now it is apparent they are likely to playa major role in the next generation of electronic devices. The theme of the School acknowledged this rapidly developing maturity.' The contributions to the volume consider not only the essential physics, but take a wider view of the topic, starting from material growth and processing, then prog ressing right through to applications with some discussion of the likely use of low dimensional devices in systems. The papers are arranged into four sections, the first of which deals with basic con cepts of semiconductor and low dimensional systems. The second section is on growth and fabrication, reviewing MBE and MOVPE methods and discussing the achievements and limitations of techniques to reduce structures into the realms of one and zero dimensions. The third section covers the crucial issue of interfaces while the final section deals with devices and device physics.

Download or read book Ultrathin Oxide Layers for Solar and Electrocatalytic Systems written by Heinz Frei and published by Royal Society of Chemistry. This book was released on 2022-01-12 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together the fundamentals and applications of ultrathin oxide layers while highlighting connections and future opportunities.

Download or read book Optical Properties of Deep Levels in III V Semiconductors written by P. W. Banks 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 Semiconductor Optics written by Claus F. Klingshirn and published by Springer Science & Business Media. This book was released on 2004-11-25 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt: New chapters add coverage of current topics such as cavity polaritons, photonic structures, bulk semiconductors and structures of reduced dimensionality. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated.