Download or read book Effect of grain boundaries on electrical properties of polycrystalline silicon written by Shubneesh Batra and published by . This book was released on 1989 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical and Electrical Properties of Grain Boundaries in Polycrystalline Silicon written by Phillip Eugene Russell and published by . This book was released on 1982 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental techniques for the investigation of the electrical and chemical properties of grain boundaries are developed and utilized for the study of cast polycrystalline silicon. Totally automated electron beam induced current (E3IC) techniques are developed, including hardware and software development, and are used for the study of recombination properties of silicon grain boundaries. Automation was used to maximize the precision and accuracy of the E3IC data and to allow large numbers of measurements to be performed to determine the effects of experimental parameters on reproducibility and beam damage. EBIC, secondary electron and optical microscopy techniques are used to characterize the grain size and structure in Wacker Silso cast polycrystalline silicon. The grain size is found to be 1.63 +/- 0.43 millimeters. Grain structure was found to be controlled by the casting process used to form the material. Twin boundaries are found to be electrically inactive. Preferential grain boundary diffusion of phosphorus in silicon grain boundaries is measured using both bevel and stain, and bevel/E3IC techniques. The effects of heat treatments at 600, 750 and 900°C are investigated extensively. An MIS device structure which does not require high temperature processing (>200°C) for fabrication is developed and utilized for these studies. EBIC analysis results show Chat grain boundary recombination velocity is substantially increased by heating cast polysilicon to temperatures as low as 60C°C, whereas no effects were seen at AOCC. Heat treatments up to 900°C are investigated. Use of complementary surface analysis techniques are developed which show that these heat treatments result in oxygen segregation to grain boundaries. ln-situ fracturing techniques for Auger electron spectroscopy and secondary ion mass spectroscopy analysis of grain boundaries?.re developed. Ton microscopy techniques are developed and used to complement the fracture studies. Local oxygen concentrations of 0.1 atomic % were measured. Eased on the time and temperature dependence of the activation of grain boundary recombination, it is concluded Chat oxygen segregation is responsible for Che activation.
Download or read book Influence of Grain Boundaries on the Electrical Properties of Polycrystalline silicon Films Progress Report 1980 1981 written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Research in 1980/81 was carried out in three areas: (i) electron diffraction experiments on diffusion bonded (welded) boundaries; (ii) combined EBIC and high voltage transmission electron microscopy in order to investigate the correlation between structure and electrical properties and (iii) passivation of the electrical activity of crystal defects with hydrogen. The diffraction experiments did not furnish new information on the structure of grain boundaries in silicon, but were valuable as a check on the previous findings. In addition, they offered the possibility to separate double diffraction effects from boundary scattering. The combined EBIC and HVTEM experiments established (for the first time) unambiguously that coherent twin boundaries per se are not electrically active. The localized electrical activity observed in coherent twin boundaries is due to the presence of intrinsic dislocations, which are partial dislocations of the Schottky type. However, not all partial dislocations studied were electrically active, for reasons which are not completely understood. The combined EBIC and HVTEM investigations showed further (again for the first time) that many of the linear boundaries which were previously assumed to be coherent twin boundaries are second order twins, and that these twins are strongly electrically active. In passivation experiments, it is necessary to separate influence of the heat treatment from those of hydrogen. Passivation reduces the activity of some, but not of all defects. Passivation is particularly effective in reducing the electrical activity of deformation induced dislocations, which conceivably have a different core structure from grown-in dislocations.
Download or read book Polycrystalline Semiconductors written by Hans J. Möller and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Grain Boundaries in Silicon Solar Cells written by and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The correlations between the electrical and compositional properties of grain boundaries in polycrystalline silicon (Si) are examined in detail. High-resolution surface analysis techniques (AES, SIMS, XPS, EELS) and microelectrical (SAM, EBIC, minority-carrier lifetime) characterization methods are used. The direct evidence for impurity segregation to the intergrain regions is presented. Effect of illumination on the grain boundary electrical characteristics are correlated with impurity compositions. Finally, the interrelationships among heat-treatment, oxygen segregation and grain boundary electrical activity are discussed.
Download or read book Electrical Properties of Grain Boundaries in Low Doped Polycrystalline Materials with Applications to Detectors written by Mazharul Huq Chowdhury and published by . This book was released on 2010 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polycrystalline Silicon for Integrated Circuit Applications written by Ted Kamins and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent years have seen silicon integrated circuits enter into an increasing number of technical and consumer applications, until they now affect everyday life, as well as technical areas. Polycrystalline silicon has been an important component of silicon technology for nearly two decades, being used first in MOS integrated circuits and now becoming pervasive in bipolar circuits, as well. During this time a great deal of informa tion has been published about polysilicon. A wide range of deposition conditions has been used to form films exhibiting markedly different properties. Seemingly contradictory results can often be explained by considering the details of the structure formed. This monograph is an attempt to synthesize much of the available knowledge about polysilicon. It represents an effort to interrelate the deposition, properties, and applications of polysilicon so that it can be used most effectively to enhance device and integrated-circuit perfor mance. As device performance improves, however, some of the proper ties of polysilicon are beginning to restrict the overall performance of integrated circuits, and the basic limitations of the properties of polysili con also need to be better understood to minimize potential degradation of circuit behavior.
Download or read book Polycrystalline Silicon for Integrated Circuits and Displays written by Ted Kamins and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycrystalline Silicon for Integrated Circuits and Displays, Second Edition presents much of the available knowledge about polysilicon. It represents an effort to interrelate the deposition, properties, and applications of polysilicon. By properly understanding the properties of polycrystalline silicon and their relation to the deposition conditions, polysilicon can be designed to ensure optimum device and integrated-circuit performance. Polycrystalline silicon has played an important role in integrated-circuit technology for two decades. It was first used in self-aligned, silicon-gate, MOS ICs to reduce capacitance and improve circuit speed. In addition to this dominant use, polysilicon is now also included in virtually all modern bipolar ICs, where it improves the basic physics of device operation. The compatibility of polycrystalline silicon with subsequent high-temperature processing allows its efficient integration into advanced IC processes. This compatibility also permits polysilicon to be used early in the fabrication process for trench isolation and dynamic random-access-memory (DRAM) storage capacitors. In addition to its integrated-circuit applications, polysilicon is becoming vital as the active layer in the channel of thin-film transistors in place of amorphous silicon. When polysilicon thin-film transistors are used in advanced active-matrix displays, the peripheral circuitry can be integrated into the same substrate as the pixel transistors. Recently, polysilicon has been used in the emerging field of microelectromechanical systems (MEMS), especially for microsensors and microactuators. In these devices, the mechanical properties, especially the stress in the polysilicon film, are critical to successful device fabrication. Polycrystalline Silicon for Integrated Circuits and Displays, Second Edition is an invaluable reference for professionals and technicians working with polycrystalline silicon in the integrated circuit and display industries.
Download or read book Fundamental Studies of Grain Boundary Passivation in Polycrystalline Silicon with Application to Improved Photovoltaic Devices A Final Research Report Covering Work Completed from February December 1979 written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Several aspects of the electrical properties of silicon grain boundaries have been studied. The temperature dependence of the zero-bias conductance and capacitance of single boundaries has been measured and shown to be in good agreement with a simple double depletion layer/thermal emission (DDL/TE) model developed to predict the transport properties of such structures. In addition, it has been shown that deconvolution of the I-V properties of some boundaries via a deconvolution scheme suggested by Pike and Seager yields effective one-electron densities of trapping states which are in good agreement with estimates obtained by low temperature electron emission measurements. Experiments have also been performed which indicate that diffusion of atomic hydrogen into silicon grain boundaries greatly reduces this density of trapping states. In properly prepared, large grained polycrystalline samples all measurable traces of grain boundary potential barriers can be removed to substantial penetration depths after several hours exposure to a hydrogen plasma at elevated temperatures. Initial experiments on prototype polysilicon solar cells have shown that this passivation process can improve AM1 efficiencies. In order to more fully understand and develop this process for improving practical multigrained cells, several device research efforts with other DOE/SERI funded contractors have been initiated.
Download or read book Thin Film Transistors Polycrystalline silicon thin film transistors written by Yue Kuo and published by Springer Science & Business Media. This book was released on 2004 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first reference on amorphous silicon and polycrystalline silicon thin film transistors that gives a systematic global review of all major topics in the field. These volumes include sections on basic materials and substrates properties, fundamental device physics, critical fabrication processes (structures, a-Si: H, dielectric, metallization, catalytic CVD), and existing and new applications. The chapters are written by leading researchers who have extensive experience with reputed track records. Thin Film Transistors provides practical information on preparing individual functional a-Si: H TFTs and poly-Si TFTs as well as large-area TFT arrays. Also covered are basic theories on the a-Si: H TFT operations and unique material characteristics. Readers are also exposed to a wide range of existing and new applications in industries.
Download or read book Influence of Grain Boundaries on the Electrical Transport Properties of Polycrystalline Si Films Progress Report written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Preliminary high resolution TEM of grain boundaries and twin boundaries in polycrystalline Si has shown that the grain boundaries may have very complicated structures. In two cases, complete spatial orientation of adjacent grains (i.e., including determination of the translation vector in the boundary) has been carried out, using the method of common reflection and lattice imaging techniques.
Download or read book Solar Energy Update written by and published by . This book was released on 1986 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Grain Boundaries in Semiconductors written by H. J. Leamy and published by North Holland. This book was released on 1982 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Photovoltaic Silicon written by Deren Yang and published by Springer. This book was released on 2019-11-28 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The utilization of sun light is one of the hottest topics in sustainable energy research. To efficiently convert sun power into a reliable energy – electricity – for consumption and storage, silicon and its derivatives have been widely studied and applied in solar cell systems. This handbook covers the photovoltaics of silicon materials and devices, providing a comprehensive summary of the state of the art of photovoltaic silicon sciences and technologies. This work is divided into various areas including but not limited to fundamental principles, design methodologies, wafering techniques/fabrications, characterizations, applications, current research trends and challenges. It offers the most updated and self-explanatory reference to all levels of students and acts as a quick reference to the experts from the fields of chemistry, material science, physics, chemical engineering, electrical engineering, solar energy, etc..
