Electrical Properties of Grain Boundaries in Low Doped Polycrystalline Materials with Applications to Detectors PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Electrical Properties of Grain Boundaries in Low Doped Polycrystalline Materials with Applications to Detectors PDF full book. Access full book title Electrical Properties of Grain Boundaries in Low Doped Polycrystalline Materials with Applications to Detectors by Mazharul Huq Chowdhury. Download full books in PDF and EPUB format.
Author: Mazharul Huq Chowdhury
Publisher:
ISBN:
Category :
Languages : en
Pages : 114
Get Book Here
Book Description
Polycrystalline materials are widely used in large area electronic devices such as flat panel x-ray image detectors, and solar cells due to their suitability to deposit over large area at low cost. The performance of polycrystalline-based flat panel detectors are showing encouraging results (good sensitivity, good resolution and acceptable dark current) and give possibility to replace existing x-ray film/screen cassette. Therefore large area polycrystalline based flat panel detectors have opened new clinical possibilities and the polycrystalline solar cells give the opportunity of manufacturing low cost photovoltaic cells. Consequently, active research has been carried out to find out suitable polycrystalline materials (e.g. HgI2, CdTe, CdZnTe, PbI2, PbO etc) for various large area applications. However a polycrystalline material is composed of micro crystallites joined together by grain boundaries (complex structure, consisting of a few atomic layers of disordered atoms) which posses trap centers for charge carriers. Therefore, grain boundaries can trap a large amount of charges during detector operation. A potential barrier for drifting carriers may exist at the grain boundary, which controls the carrier mobility. Moreover, the performance of these polycrystalline detectors are affected due to the polarization phenomena (any change in the performance of the detector after the detector biasing) under applied bias. Therefore, in this research work, an analytical model is developed to study the electrical properties (electric field and potential distributions, potential barrier height, and polarization phenomenon) of polycrystalline materials at different doping levels for detector and solar cell applications by considering an arbitrary amount of grain boundary charge and a finite width of grain boundary region. The general grain boundary model is also applicable to highly doped polycrystalline materials. The electric field and potential distributions are obtained by solving the Poisson's equation in both depleted grains and grain boundary regions. The electric field and potential distributions across the detector are analyzed under various doping, trapping and applied biases. The electric field collapses, i.e., a nearly zero average electric field region exists in some part of the biased detector at high trapped charge densities at the grain boundaries. The model explains the conditions of existence of a zero average field region, i.e., it explains the polarization mechanisms in polycrystalline materials. The potential barrier at the grain boundary exists if the electric field changes its sign at the opposite side of the grain boundary. The potential barrier does not exist in all grain boundaries in the low doped polycrystalline detector and it never exists in intrinsic polycrystalline detectors under applied bias condition provided there is no charge trapping in the grain.
Author: Mazharul Huq Chowdhury
Publisher:
ISBN:
Category :
Languages : en
Pages : 114
Get Book Here
Book Description
Polycrystalline materials are widely used in large area electronic devices such as flat panel x-ray image detectors, and solar cells due to their suitability to deposit over large area at low cost. The performance of polycrystalline-based flat panel detectors are showing encouraging results (good sensitivity, good resolution and acceptable dark current) and give possibility to replace existing x-ray film/screen cassette. Therefore large area polycrystalline based flat panel detectors have opened new clinical possibilities and the polycrystalline solar cells give the opportunity of manufacturing low cost photovoltaic cells. Consequently, active research has been carried out to find out suitable polycrystalline materials (e.g. HgI2, CdTe, CdZnTe, PbI2, PbO etc) for various large area applications. However a polycrystalline material is composed of micro crystallites joined together by grain boundaries (complex structure, consisting of a few atomic layers of disordered atoms) which posses trap centers for charge carriers. Therefore, grain boundaries can trap a large amount of charges during detector operation. A potential barrier for drifting carriers may exist at the grain boundary, which controls the carrier mobility. Moreover, the performance of these polycrystalline detectors are affected due to the polarization phenomena (any change in the performance of the detector after the detector biasing) under applied bias. Therefore, in this research work, an analytical model is developed to study the electrical properties (electric field and potential distributions, potential barrier height, and polarization phenomenon) of polycrystalline materials at different doping levels for detector and solar cell applications by considering an arbitrary amount of grain boundary charge and a finite width of grain boundary region. The general grain boundary model is also applicable to highly doped polycrystalline materials. The electric field and potential distributions are obtained by solving the Poisson's equation in both depleted grains and grain boundary regions. The electric field and potential distributions across the detector are analyzed under various doping, trapping and applied biases. The electric field collapses, i.e., a nearly zero average electric field region exists in some part of the biased detector at high trapped charge densities at the grain boundaries. The model explains the conditions of existence of a zero average field region, i.e., it explains the polarization mechanisms in polycrystalline materials. The potential barrier at the grain boundary exists if the electric field changes its sign at the opposite side of the grain boundary. The potential barrier does not exist in all grain boundaries in the low doped polycrystalline detector and it never exists in intrinsic polycrystalline detectors under applied bias condition provided there is no charge trapping in the grain.
Author: Hans J. Möller
Publisher: Springer Science & Business Media
ISBN: 3642934137
Category : Technology & Engineering
Languages : en
Pages : 399
Get Book Here
Book Description
This book summarizes the most recent aspects of polycrystalline semiconductors as presented at the conference Polycrystalline Semiconductors - Grain Boundaries and Interfaces. It contains 12 review articles on selected topics written by experts in their fields and 41 complementary contributed papers. The structure, chemistry and physics of grain boundaries and other interfaces are experimentally and theoretically studied. Aspects of the technologically important polycrystalline silicon are discussed in detail. Also covered are other polycrystalline semiconductors, germanium and compound semiconductors, that are currently of interest in fundamental research and in the technology of solar cells and thin film devices. Anyone interested in polycrystalline semiconductors will be able to use this comprehensive collection to advantage. It also suggests directions for new research and development.
Author: A. Bhalla
Publisher: CRC Press
ISBN: 9782881243370
Category : Detectors
Languages : en
Pages : 402
Get Book Here
Book Description
Author: James Ransley
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Grain boundaries form the basis of an important Josephson junction technology in the cuprates and also limit the superconducting critical currents attainable in practical, polycrystalline materials. An improved understanding of these defects is therefore important for applications. The status of the current understanding of cuprate grain boundaries is summarised and experimental investigations are presented, focusing on the less well understood high angle boundaries. Measurements of the capacitance of grain boundaries in the overdoped superconductor Y1-xCaxBa2Cu3O7-8, were performed as a function of the calcium content, using the Josephson coupling across the boundaries. Particular care was taken to eliminate the effects of heating and stray capacitance due to the substrate. The effect of thermal noise was also assessed. These measurements provide important information about the area and the width of the grain boundaries, that highlights their inhomogeneous nature. A new technique was applied to measure the normal state properties of YBa2Cu3O7-8 grain boundaries above the critical temperature. Since the resistance of the adjacent material at high temperatures is comparable to, or greater than, that of the grain boundary a compensating Wheatstonebridge structure was used. The errors involved in this technique are carefully assessed and quantified. The normal state resistance of a number of different grain boundary orientations was measured from room temperature to the critical temperature. Detailed characterisation of the grain boundaries, including measurements of the critical current and the current voltage characteristics at low temperatures, was performed. The results obtained are used to assess the validity of the various theories for the grain boundary electrical structure. A tunneling model that accounts for the band structure of the material is developed and applied to potential barriers consistent with a band bending model. This theory is shown to provide a convincing account of the experimental results presented in this thesis.
Author: Ghenadii Korotcenkov
Publisher: Springer Nature
ISBN: 3031240006
Category : Technology & Engineering
Languages : en
Pages : 700
Get Book Here
Book Description
The reference provides interdisciplinary discussion for diverse II-VI semiconductors with a wide range of topics. The third volume of a three volume set, the book provides an up-to-date account of the present status of multifunctional II-VI semiconductors, from fundamental science and processing to their applications as various sensors, biosensors, and radiation detectors, and based on them to formulate new goals for the further research. The chapters in this volume provide a comprehensive overview of the manufacture, parameters and principles of operation of these devices. The application of these devices in various fields such medicine, agriculture, food quality control, environment monitoring and others is also considered. The analysis carried out shows the great potential of II-VI semiconductor-based sensors and detectors for these applications. Considers solid-state radiation detectors based on semiconductors of II-VI group and their applications; Analyzes the advantages of II-VI compounds to develop chemical and optical gas and ion sensors; Describes all types of biosensors based on II-VI semiconductors and gives examples of their use in various fields.
Author: Gurinder Kaur Ahluwalia
Publisher: Springer
ISBN: 331941190X
Category : Technology & Engineering
Languages : en
Pages : 472
Get Book Here
Book Description
This book introduces readers to a wide range of applications for elements in Group 16 of the periodic table, such as, optical fibers for communication and sensing, X-ray imaging, electrochemical sensors, data storage devices, biomedical applications, photovoltaics and IR detectors, the rationale for these uses, the future scope of their applications, and expected improvements to existing technologies. Following an introductory section, the book is broadly divided into three parts—dealing with Sulfur, Selenium, and Tellurium. The sections cover the basic structure of the elements and their compounds in bulk and nanostructured forms; properties that make these useful for various applications, followed by applications and commercial products. As the global technology revolution necessitates the search for new materials and more efficient devices in the electronics and semiconductor industry, Applications of Chalcogenides: S, Se, and Te is an ideal book for a wide range of readers in industry, government and academic research facilities looking beyond silicon for materials used in the electronic and optoelectronic industry as well as biomedical applications.
Author:
Publisher: Newnes
ISBN: 0080965334
Category : Technology & Engineering
Languages : en
Pages : 5485
Get Book Here
Book Description
Comprehensive Materials Processing, Thirteen Volume Set provides students and professionals with a one-stop resource consolidating and enhancing the literature of the materials processing and manufacturing universe. It provides authoritative analysis of all processes, technologies, and techniques for converting industrial materials from a raw state into finished parts or products. Assisting scientists and engineers in the selection, design, and use of materials, whether in the lab or in industry, it matches the adaptive complexity of emergent materials and processing technologies. Extensive traditional article-level academic discussion of core theories and applications is supplemented by applied case studies and advanced multimedia features. Coverage encompasses the general categories of solidification, powder, deposition, and deformation processing, and includes discussion on plant and tool design, analysis and characterization of processing techniques, high-temperatures studies, and the influence of process scale on component characteristics and behavior. Authored and reviewed by world-class academic and industrial specialists in each subject field Practical tools such as integrated case studies, user-defined process schemata, and multimedia modeling and functionality Maximizes research efficiency by collating the most important and established information in one place with integrated applets linking to relevant outside sources
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Pavel Lejcek
Publisher: Springer Science & Business Media
ISBN: 3642125050
Category : Technology & Engineering
Languages : en
Pages : 249
Get Book Here
Book Description
Grain boundaries are important structural components of polycrystalline materials used in the vast majority of technical applications. Because grain boundaries form a continuous network throughout such materials, their properties may limit their practical use. One of the serious phenomena which evoke these limitations is the grain boundary segregation of impurities. It results in the loss of grain boundary cohesion and consequently, in brittle fracture of the materials. The current book deals with fundamentals of grain boundary segregation in metallic materials and its relationship to the grain boundary structure, classification and other materials properties.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1028
Get Book Here
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
