Download or read book Improved Techniques for the Growth of High Quality Cadmium Telluride Crystals written by R. S. Feigelson and published by . This book was released on 1985 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes two years' work as part of a multiyear program on improved techniques for the growth of high quality cadmium telluride crystals and represents one of the most comprehensive studies of melt growth and defect characterization in CdTe reported to date. Extensive melt growth studied were carried out using te vertical Bridgman method. Growth parameters were systematically varied in order to determine the influence of seed orientation, thermal environment, and growth rate on crystal quality. Growth interface shapes were revealed using autoradiographic dopant tracing methods. Melt thermal profiling was also carried out to further evaluate growth interface shapes. Controlled convex growth interface shapes were generated by using the heat exchanger method. By this means some improvement in grain structure of the typically polycrystalline boules was accomplished. Low frequency melt vibrations during growth were also observed to improve grain structure and reduce dislocation density. Extensive defect characterization was alos carried out using chemical etching methods, and later, synchrotron x-ray topography. Comparative studies of a broad selection of commercial CdTe substrates was carried out, and extensive defect structure was observed in all cases. Reduced dislocation densities and defect structures were accomplished using both low amplitude melt vibrations and doping with In 1IIC13. In the second case, solution hardening was assumed to be the mechanism responsible. For the case of melt vibration, the mechanism is not yet understood.
Download or read book Research and Development on Single Crystal High Resistivity Cadmium Telluride for Use as a Gamma ray Spectrometer written by Kenneth R. Zanio and published by . This book was released on 1971 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research in Progress written by and published by . This book was released on 1983 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth of Cadmium Telluride Under Controlled Heat Transfer Conditions written by August F. Witt and published by . This book was released on 1986 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thrust of this research project was directed at the development of new approaches leading to growth of CdTe single crystals with improved crystalline and chemical perfection. In pursuit of this objective a theoretical analysis was made of the stability of the growth interface as a function of crystallographic orientation. Using the concept of dangling bond densities, it was found that experimentally observed solitary and lamellar twinning phenomena during growth can be directly related to anisotropy in the energetics of unavoidably curved crystal melt interfaces. The theoretical results obtained led to the development of a vertical Bridgman growth configuration in which heat transfer control is accomplished through an axially aligned heat exchange system comprising a heat pipe, a gradient control zone, and a heat levelling device. As an alternate approach to melt growth of CdTe, the suitability of the high pressure liquid encapsulation Czochralski technique (HP-LEC) was investigated. In the course of this study, analytical techniques, including IR transmission microscopy with image processing and absorption spectroscopy of the optical band edge, were developed and applied to investigations of the bulk defect structure. The results obtained during this research program constitute the basis for extensive DARPA, Air Force, and NASA sponsored research on growth of III-V and II-VI compound semiconductor systems.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Growth and Homogeneity Characterization of Mercury Cadmium Telluride Crystals written by Fred Pollak and published by . This book was released on 1979 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have grown epitaxial layers of mercury telluride by the new method of current controlled liquid phase epitaxy (CCLPE). We have designed and constructed the apparatus necessary to grow highly homogeneous crystalline layers of this material by this new technique. The design has been tested repeatedly and a number of crystalline layers have been successfully grown. These layers have been studied micrographically and with the use of X-ray diffraction and electrolyte electroreflectance techniques. (Author).
Download or read book Vapor Crystal Growth Technology Development Application to Cadmium Telluride written by Franz Rosenberger and published by . This book was released on 1991 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Emerging Materials written by Laxman Raju Thoutam and published by Springer Nature. This book was released on 2022-05-13 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as a quick guide on the latest material systems including their synthesis, fabrication and characterization techniques. It discusses recent developments in different material systems and discusses their novel applications in various branches of science and engineering. The book briefs latest computational tools and techniques that are used to discover new material systems. The book also briefs applications of new emerging materials in various fields including, healthcare, sensors, opto-electronics, high power devices and nano-electronics. This book helps to create a synergy between computational and experimental research methods to better understand a particular material system.
Download or read book High Z Materials for X ray Detection written by Leonardo Abbene and published by Springer Nature. This book was released on 2023-01-01 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will provide readers with a good overview of some of most recent advances in the field of High-Z materials. There will be a good mixture of general chapters in both technology and applications in opto-electronics, X-ray detection and emerging optoelectronics applications. The book will have an in-depth review of the research topics from world-leading specialists in the field.
Download or read book CdTe and Related Compounds Physics Defects Hetero and Nano structures Crystal Growth Surfaces and Applications written by and published by Elsevier. This book was released on 2009-11-11 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost thirty years after the remarkable monograph of K. Zanio and the numerous conferences and articles dedicated since that time to CdTe and CdZnTe, after all the significant progresses in that field and the increasing interest in these materials for several extremely attractive industrial applications, such as nuclear detectors and solar cells, the edition of a new enriched and updated monograph dedicated to these two very topical II-VI semiconductor compounds, covering all their most prominent, modern and fundamental aspects, seemed very relevant and useful. - Detailed coverage of the main topics associated with the very topical II-VI semiconductor compound CdTe and its alloy CZT - Review of the CdTe recent developments - Fundamental background of many topics clearly introduced and exposed
Download or read book Springer Handbook of Electronic and Photonic Materials written by Safa Kasap and published by Springer Science & Business Media. This book was released on 2007-08-01 with total page 1409 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributions from well known and respected researchers throughout the world Thorough coverage of electronic and opto-electronic materials that today's electrical engineers, material scientists and physicists need Interdisciplinary approach encompasses research in disciplines such as materials science, electrical engineering, chemical engineering, mechanical engineering, physics and chemistry
Download or read book Technical Abstract Bulletin written by and published by . This book was released on 1982 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Isotopes and Radiation Technology written by and published by . This book was released on 1971 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Strategies and Challenges to Improve Single Crystal Yield and Detector Properties of Cadmium Zinc Telluirde that Is Telluride Grown Via Accelerated Crucible Rotation written by Saketh Kakkireni and published by . This book was released on 2020 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid-state radiation detection finds its applications in numerous fields ranging from nuclear medicine to astrophysics. Although Semiconductors offer better energy and spatial resolution than Scintillators, their market share is limited by the cost, availability and need for cryogenic cooling. Cadmium Zinc Telluride (CZT) is a compound semiconductor with attractive properties for compact device technology for detection of X-rays and Gamma-rays. Over the past few decades' numerous efforts are made to grow high-quality CZT, unfortunately to-date it's application is limited by large-scale production and cost. Poor thermo-physical properties of CZT coupled with no strong growth direction make it a challenge to achieve high yield of single crystalline material. Current industrial flux growth technique is inherently limited by slow growth rates and requires post-processing. The solution may be found in the Accelerated Crucible Rotation Technique (ACRT), where the crystal growth is achieved under a forced convective regime involving periodic rotation of the growth crucible. ACRT induced flow patterns can homogenize the melt thereby enabling faster growth rates and eliminate the need for post-processing. Our preliminary results, presented here, show that ACRT can reduce the production time by a factor of four. Additionally, the application of ACRT has provided the potential for scale up the growth process. Also discussed are challenges and future strategies in ACRT coupled CZT growth. Successful completion of this work will enable the use of CZT in the next generation imaging systems as well as provide a better foundation for understanding and implementing ACRT in other crystal growth systems. Successful seeding and superior detector resolutions are demonstrated.
Download or read book Handbook of II VI Semiconductor Based Sensors and Radiation Detectors written by Ghenadii Korotcenkov and published by Springer Nature. This book was released on 2023-04-20 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-volumes book “Handbook of II-VI Semiconductor-Based Sensors and Radiation Detectors” is the first to cover both chemical sensors and biosensors and all types of photodetectors and radiation detectors based on II-VI semiconductors. It contains a comprehensive and detailed analysis of all aspects of the application of II-VI semiconductors in these devices. The first volume "Materials and Technologies" of a three-volume set describes the physical, chemical and electronic properties of II-VI compounds, which give rise to an increased interest in these semiconductors. Technologies that are used in the development of various devices based on II-VI connections, such as material synthesis, deposition, characterization, processing, and device fabrication, are also discussed in detail in this volume. It covers also topics related to synthesis and application of II-VI-based nanoparticles and quantum dots, as well their toxicity, biocompatibility and biofunctionalization.
Download or read book Vapor Crystal Growth Technology Development written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-02 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growth of bulk crystals by physical vapor transport was developed and applied to cadmium telluride. The technology makes use of effusive ampoules, in which part of the vapor contents escapes to a vacuum shroud through defined leaks during the growth process. This approach has the advantage over traditional sealed ampoule techniques that impurity vapors and excess vapor constituents are continuously removed from the vicinity of the growing crystal. Thus, growth rates are obtained routinely at magnitudes that are rather difficult to achieve in closed ampoules. Other advantages of this effusive ampoule physical vapor transport (EAPVT) technique include the predetermination of transport rates based on simple fluid dynamics and engineering considerations, and the growth of the crystal from close to congruent vapors, which largely alleviates the compositional nonuniformities resulting from buoyancy driven convective transport. After concisely reviewing earlier work on improving transport rates, nucleation control, and minimization of crystal wall interactions in vapor crystal growth, a detail account is given of the largely computer controlled EAPVT experimentation. Rosenberger, Franz and Banish, Michael and Duval, Walter M. B. Glenn Research Center...
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1986-07 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:
