Download or read book Understanding Defects in Germanium and Silicon for Optoelectronic Energy Conversion written by Neil Sunil Patel and published by . This book was released on 2016 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores bulk and interface defects in germanium (Ge) and silicon (Si) with a focus on understanding the impact defect related bandgap states will have on optoelectronic applications. Optoelectronic devices are minority carrier devices and are particularly sensitive to defect states which can drastically reduce carrier lifetimes in small concentrations. We performed a study of defect states in Sb-doped germanium by generation of defects via irradiation followed by subsequent characterization of electronic properties via deep-level transient spectroscopy (DLTS). Cobalt-60 gamma rays were used to generate isolated vacancies and interstitials which diffuse and react with impurities in the material to form four defect states (E37, E30, E22, and E21) in the upper half of the bandgap. Irradiations at 77 K and 300 K as well as isothermal anneals were performed to characterize the relationships between the four observable defects. E37 is assigned to the Sb donor-vacancy associate (E-center) and is the only vacancy containing defect giving an estimate of 2 x 1011 cm-3 Mrad-1 for the uncorrelated vacancy-interstitial pair introduction rate. E37 decays by dissociation and vacancy diffusion to a sink present in a concentration of 1012 cm-3. The remaining three defect states are interstitial associates and transform among one another. Conversion ratios between E22, E21, and E30 indicate that E22 likely contains two interstitials. The formation behavior of E22 after irradiation in liquid nitrogen indicates that E30 is required for formation of E22. Eight defect states previously unseen after gamma irradiation were observed and characterized after irradiation by alpha and neutron sources. Their absence after gamma irradiation indicates that defect formation requires collision cascades. We demonstrate electrically pumped lasing from Ge epitaxially grown on Si. Lasing is observed over a ~200nm bandwidth showing that this system holds promise for low-cost on-chip communications applications via silicon microphotonics. The observed large threshold currents are determined to be largely a result of recombination due to threading dislocations. We estimate that recombination by threading dislocations becomes negligible when threading dislocation density is

Download or read book Silicon Germanium and Their Alloys written by Gudrun Kissinger and published by CRC Press. This book was released on 2014-12-09 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the vast knowledge accumulated on silicon, germanium, and their alloys, these materials still demand research, eminently in view of the improvement of knowledge on silicon-germanium alloys and the potentialities of silicon as a substrate for high-efficiency solar cells and for compound semiconductors and the ongoing development of nanodevic

Download or read book Extended Defects in Germanium written by Cor Claeys and published by Springer Science & Business Media. This book was released on 2008-12-29 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim is to give an overview of the physics of extended defects in Germanium, i.e. dislocations (line defects), grain boundaries, stacking faults, twins and {311} defects (two-dimensional defects) and precipitates, bubbles, etc. The first part covers fundamentals, describing the crystallographic structure and other physical and electrical properties, mainly of dislocations. Since dislocations are essential for the plastic deformation of Germanium, methods for analysis and imaging of dislocations and to evaluate their structure are described. Attention is given to the electrical and optical properties, which are important for devices made in dislocated Ge. The second part treats the creation of extended defects during wafer and device processing. Issues are addressed such as defect formation during ion implantation, necessary to create junctions, which are an essential part in every device type. Extended defects are also created during the deposition of thin or thick epitaxial layers on other substrates, which are important for optoelectronic and photovoltaic applications. In brief, the book is intended to provide a fundamental understanding of the extended-defect formation during Ge materials and device processing, providing ways to distinguish harmful from less detrimental defects and should point out ways for defect engineering and control.

Download or read book The Design Fabrication and Characterization of Silicon germanium Optoelectronic Devices Grown by Molecular Beam Epitaxy written by Nathan Anthony Sustersic and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, Ge and SiGe devices have been actively investigated for potential optoelectronic applications such as germanium solar cells for long wavelength absorption, quantum-dot intermediate band solar cells (IBSCs), quantum-dot infrared photodetectors (QDIPs) and germanium light-emitting diodes (LEDs). Current research into SiGe based optoelectronic devices is heavily based on nanostructures which employ quantum confinement and is at a stage where basic properties are being studied in order to optimize growth conditions necessary for incorporation into future devices. Ge and SiGe based devices are especially attractive due to ease of monolithic integration with current Si-based CMOS processing technology, longer carrier lifetime, and reduced phonon scattering. Defect formation and transformation was studied in SiGe layers grown on Si and Ge (100) substrates. The epitaxial layers were grown with molecular beam epitaxy (MBE) and characterized by X-ray measurements in order to study the accommodation of elastic strain energy in the layers. The accommodation of elastic strain energy specifies the amount of point defects created on the growth surface which may transform into extended crystalline defects in the volume of the layers. An understanding of crystalline defects in high lattice mismatched epitaxial structures is critical in order to optimize growth procedures so that epitaxial structures can be optimized for specific devices such as Ge based solar cells. Considering the optimization of epitaxial layers based on the structural transformation of point defects, Ge solar cells were fabricated and investigated using current-voltage measurements and quantum efficiency data. These Ge solar cells, optimized for long wavelength absorption, were fabricated to be employed in a bonded Ge/Si solar cell device. The doping of self-assembled Ge quantum dot structures grown on Si (100) was investigated using atomic force microscopy (AFM) and photoluminescence (PL) spectroscopy. This is of special interest for Ge quantum dots employed in active device structures where the effect of Ge dot and Si buffer layer doping on structural and luminescence properties must be well understood. Large Ge islands known as "superdomes" were fabricated by MBE and characterized by scanning electron microscopy (SEM), AFM, and Raman spectroscopy. These Ge nanostructures have the potential to become a direct material through band-structure modification by introducing moderate tensile strain into the Ge layer and band-filling. The results of this research on the growth, fabrication, and characterization of SiGe materials, structures, and devices may be useful for applications in the fields of energy, communication, computation, and remote sensing.

Download or read book Defects in Microelectronic Materials and Devices written by Daniel M. Fleetwood and published by CRC Press. This book was released on 2008-11-19 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncover the Defects that Compromise Performance and ReliabilityAs microelectronics features and devices become smaller and more complex, it is critical that engineers and technologists completely understand how components can be damaged during the increasingly complicated fabrication processes required to produce them.A comprehensive survey of defe

Download or read book Liquid Phase Epitaxy of Electronic Optical and Optoelectronic Materials written by Peter Capper and published by John Wiley & Sons. This book was released on 2007-08-20 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid-Phase Epitaxy (LPE) is a technique used in the bulk growth of crystals, typically in semiconductor manufacturing, whereby the crystal is grown from a rich solution of the semiconductor onto a substrate in layers, each of which is formed by supersaturation or cooling. At least 50% of growth in the optoelectronics area is currently focussed on LPE. This book covers the bulk growth of semiconductors, i.e. silicon, gallium arsenide, cadmium mercury telluride, indium phosphide, indium antimonide, gallium nitride, cadmium zinc telluride, a range of wide-bandgap II-VI compounds, diamond and silicon carbide, and a wide range of oxides/fluorides (including sapphire and quartz) that are used in many industrial applications. A separate chapter is devoted to the fascinating field of growth in various forms of microgravity, an activity that is approximately 30-years old and which has revealed many interesting features, some of which have been very surprising to experimenters and theoreticians alike. Covers the most important materials within the field The contributors come from a wide variety of countries and include both academics and industrialists, to give a balanced treatment Builds-on an established series known in the community Highly pertinent to current and future developments in telecommunications and computer-processing industries.

Download or read book Optoelectronics written by P. Predeep and published by BoD – Books on Demand. This book was released on 2011-09-26 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoelectronics - Materials and Techniques is the first part of an edited anthology on the multifaceted areas of optoelectronics by a selected group of authors including promising novices to the experts in the field. Photonics and optoelectronics are making an impact multiple times the semiconductor revolution made on the quality of our life. In telecommunication, entertainment devices, computational techniques, clean energy harvesting, medical instrumentation, materials and device characterization and scores of other areas of R

Download or read book 1994 IEEE First World Conference on Photovoltaic Energy Conversion written by and published by . This book was released on 1994 with total page 1318 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Materials 1991 1992 written by J. Binner and published by Elsevier. This book was released on 2013-10-22 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Materials 1991-1992, I. Source Book focuses on the properties, characteristics, reactions, applications, and composition of ceramics, composites, and plastics. The publication first elaborates on ceramics, including markets, materials, applications, processing, equipment, standards, health, safety, the environment, research initiatives, and industry news. Topics include joint ventures/agreements, powder processing, furnaces, bioceramics, electronics, superconductors, oxide films, silica, sensors, and superconductors. The manuscript also takes a look at composites, as well as markets, materials, applications, processing, non-destructive evaluation, testing, health, safety, and the environment, research initiatives, and industry news. Concerns include restructuring, takeovers and mergers, recycling, health and safety, test development, data generation, manufacturing processes, tooling, coatings, general engineering, aerospace, automotive, and boom in advanced composites. The book then ponders on plastics, including markets, materials, applications, processing, equipment, health, safety, the environment, and industry news. The publication is a valuable reference for readers interested in the properties, applications, processing, and composition of ceramics, composites, and plastics.

Download or read book Materials in Energy Conversion Harvesting and Storage written by Kathy Lu and published by John Wiley & Sons. This book was released on 2014-08-07 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: First authored book to address materials' role in the quest for the next generation of energy materials Energy balance, efficiency, sustainability, and so on, are some of many facets of energy challenges covered in current research. However, there has not been a monograph that directly covers a spectrum of materials issues in the context of energy conversion, harvesting and storage. Addressing one of the most pressing problems of our time, Materials in Energy Conversion, Harvesting, and Storage illuminates the roles and performance requirements of materials in energy and demonstrates why energy materials are as critical and far-reaching as energy itself. Each chapter starts out by explaining the role of a specific energy process in today’s energy landscape, followed by explanation of the fundamental energy conversion, harvesting, and storage processes. Well-researched and coherently written, Materials in Energy Conversion, Harvesting, and Storage covers: The availability, accessibility, and affordability of different energy sources Energy production processes involving material uses and performance requirements in fossil, nuclear, solar, bio, wind, hydrothermal, geothermal, and ocean energy systems Issues of materials science in energy conversion systems Issues of energy harvesting and storage (including hydrogen storage) and materials needs Throughout the book, illustrations and images clarify and simplify core concepts, techniques, and processes. References at the end of each chapter serve as a gateway to the primary literature in the field. All chapters are self-contained units, enabling instructors to easily adapt this book for coursework. This book is suitable for students and professors in science and engineering who look to obtain comprehensive understanding of different energy processes and materials issues. In setting forth the latest advances and new frontiers of research, experienced materials researchers and engineers can utilize it as a comprehensive energy material reference book.

Download or read book Materials for Optoelectronic Devices OEICs and Photonics written by H. Schlötterer and published by Elsevier. This book was released on 1991-10-08 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the contributions in this volume is to give a current overview on the basic properties and applications of semiconductor and nonlinear optical materials for optoelectronics and integrated optics. They provide a cross-linkage between different materials (III-V, II-VI, Si-Ge, glasses, etc.), various sample dimensions (from bulk crystals to quantum dots), and a range of techniques for growth (LPE to MOMBE) and for processing (from surface passivation to ion beams). Major growth techniques and materials are discussed, including the sophisticated technologies required to exploit the exciting properties of low dimensional semiconductors. These proceedings will prove an invaluable guide to the current state of optoelectronic and nonlinear optical materials development, as well as indicating trends and also future markets for optoelectronic devices.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 1102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Information Circular written by and published by . This book was released on 1988 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gallium and Gallium Arsenide written by Deborah A. Kramer and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of the 1986 Sand and Gravel Mining Workforce written by Shail J. Butani and published by . This book was released on 1988 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Halide Perovskites written by Tze-Chien Sum and published by John Wiley & Sons. This book was released on 2019-03-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real insight from leading experts in the field into the causes of the unique photovoltaic performance of perovskite solar cells, describing the fundamentals of perovskite materials and device architectures. The authors cover materials research and development, device fabrication and engineering methodologies, as well as current knowledge extending beyond perovskite photovoltaics, such as the novel spin physics and multiferroic properties of this family of materials. Aimed at a better and clearer understanding of the latest developments in the hybrid perovskite field, this is a must-have for material scientists, chemists, physicists and engineers entering or already working in this booming field.

Download or read book Picosecond Optoelectronic Devices written by Chi H. Lee and published by Elsevier. This book was released on 2012-12-02 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Picosecond Optoelectronic Devices reviews the major developments in the field of picosecond optoelectronics. This book discusses the picosecond pulse generation with semiconductor diode lasers; gigabit optical pulse generation in integrated lasers and applications; and picosecond photoconductors. The picosecond optoelectronic devices based on optically injected electron-hole plasma; pulse forming with optoelectronic switches; and high-power picosecond switching in bulk semiconductors are also elaborated. This text likewise discusses the sub-picosecond electrical sampling and applications; InP optoelectronic switches; and picosecond chronography. Other topics include the picosecond optical control of transferred-electron devices; optoelectronic switch for pulsed power; and responses of TEDs to picosecond optical pulses. This publication is a good source for electrical engineers and researchers conducting work on picosecond optoelectronics.