Download or read book Metal Impurity Redistribution in Crystalline Silicon for Photovoltaic Application written by and published by . This book was released on 2014 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multicrystalline silicon, which is among the most common materials for solar cells [3], contains extended defects like grain boundaries and dislocations and a high amount of metal impurities potentially reducing the solar cell efficiency [1,7]. In order to reduce the detrimental effect of metal impurities on the efficiency of multicrystalline solar cells, the metal impurities can be redistributed into electrical inactive areas of the solar cell (gettering) [12] or at few large accumulation sites, e.g. at grain boundaries [16]. In this work the interaction of metal impurities with extended d...

Download or read book Metal Impurities in N type Crystalline Silicon for Photovoltaics written by Ashley Elizabeth Morishige and published by . This book was released on 2016 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystalline silicon is the dominant technology in the rapidly-growing photovoltaics (PV) industry, but significant cost reduction is still required before widespread grid parity is achieved. One-quarter of the cost of a PV module is the Si wafer. One way to reduce the cost/kWh of PV is to identify a higher-efficiency "drop-in" substitute for the currently dominant p-type multicrystalline silicon (mc-Si) wafer. This thesis explores one class of wafer substitute: n-type silicon. This material is thought to have higher defect tolerance than p-type, but practical mc-Si cell efficiencies have remained lower than in p-type. This thesis explores why, using a combination of simulation and experiment. In particular, synchrotron-based micro-X-ray fluorescence mapping is used to non-destructively evaluate metal impurity evolution during processing. This thesis demonstrates that metal impurity redistribution during solar cell processing is similar in n- and p-type mc-Si but the relative electrical impact of point defect and precipitated impurities is different, requiring different approaches to processing. It has been hypothesized and shown indirectly that metal impurities redistribute similarly in n- and p-type mc-Si during processing. To confirm this hypothesis, I combined Fermi-level analysis with direct measurements of the metal distribution before and after an industrially-relevant range of gettering processes. This study confirmed that the understanding of metal redistribution developed for p-type mc-Si is directly applicable to n-type mc-Si. To improve the understanding of metal impurity movement during solar cell processing, I developed a tool using Sentaurus TCAD software to visualize in 2D metal redistribution and the resulting recombination activity. I also performed an analytical review of the state of the art of crystalline silicon solar cell process simulation tools. The analysis elucidated the key physics of impurity gettering during solar cell processing and enabled guidelines for efficient, yet accurate, solar cell process simulations. To quantify the recombination activity of precipitated iron in n-type crystalline silicon, I directly measured the iron content and recombination strength of iron precipitates in n-type crystalline silicon using a suite of micro-characterization tools. I found that iron-containing precipitates are highly recombination active in n-type Si and that the precipitate size is correlated with its recombination strength. To enable this study, I benchmarked the use of a new high-throughput synchrotron-based data collection mode called on-the-fly scanning. To bring the level of sophistication of predictive simulation for p-type mc-Si to that of n-type mc-Si, I developed a simulation tool that calculates the redistribution of iron throughout the solar cell process and the resulting injection-dependent electrical performance of the wafer for both p- and n-type Si. Analysis using this tool indicates that p-type mc-Si usually requires point defect remediation during a slow cooling process, but for n-type mc-Si, dissolving iron-rich precipitates during shorter, higher temperature processing is often sufficient. Efficiency entitlement curves predict that n-type mc-Si can support 20% efficient solar cells. Finally, knowledge of defects developed for Si wafers was applied to a key challenge facing the PV industry at the PV system level. In the field, degradation of next-generation industrial p-type mc-Si PV modules has been observed. Leveraging the fundamental understanding of the physics of impurities in Si wafers, the recombination parameters of the root-cause defect were quantified. Building on the rich literature of p-type multicrystalline silicon, this thesis enables predictive engineering of all crystalline silicon materials from wafer growth to module performance in the field.

Download or read book Advanced Silicon Materials for Photovoltaic Applications written by Sergio Pizzini and published by John Wiley & Sons. This book was released on 2012-06-07 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today, the silicon feedstock for photovoltaic cells comes from processes which were originally developed for the microelectronic industry. It covers almost 90% of the photovoltaic market, with mass production volume at least one order of magnitude larger than those devoted to microelectronics. However, it is hard to imagine that this kind of feedstock (extremely pure but heavily penalized by its high energy cost) could remain the only source of silicon for a photovoltaic market which is in continuous expansion, and which has a cumulative growth rate in excess of 30% in the last few years. Even though reports suggest that the silicon share will slowly decrease in the next twenty years, finding a way to manufacture a specific solar grade feedstock in large quantities, at a low cost while maintaining the quality needed, still remains a crucial issue. Thin film and quantum confinement-based silicon cells might be a complementary solution. Advanced Silicon Materials for Photovoltaic Applications has been designed to describe the full potentialities of silicon as a multipurpose material and covers: Physical, chemical and structural properties of silicon Production routes including the promise of low cost feedstock for PV applications Defect engineering and the role of impurities and defects Characterization techniques, and advanced analytical techniques for metallic and non-metallic impurities Thin film silicon and thin film solar cells Innovative quantum effects, and 3rd generation solar cells With contributions from internationally recognized authorities, this book gives a comprehensive analysis of the state-of-the-art of process technologies and material properties, essential for anyone interested in the application and development of photovoltaics.

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..

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1978 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solar Silicon Processes written by Bruno Ceccaroli and published by CRC Press. This book was released on 2016-10-03 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycrystalline silicon (commonly called "polysilicon") is the material of choice for photovoltaic (PV) applications. Polysilicon is the purest synthetic material on the market, though its processing through gas purification and decomposition (commonly called "Siemens" process) carries high environmental risk. While many current optoelectronic applications require high purity, PV applications do not and therefore alternate processes and materials are being explored for PV grade silicon. Solar Silicon Processes: Technologies, Challenges, and Opportunities reviews current and potential future processing technologies for PV applications of solar silicon. It describes alternative processes and issues of material purity, cost, and environmental impact. It covers limits of silicon use with respect to high-efficiency solar cells and challenges arising from R&D activities. The book also defines purity requirements and purification processes of metallurgical grade silicon (MG-Si) and examines production of solar grade silicon by novel processes directly from MG-Si and/or by decomposition of silane gas in a fluidized bed reactor (FBR). Furthermore, the book: Analyzes past research and industrial development of low-cost silicon processes in view of understanding future trends in this field. Discusses challenges and probability of success of various solar silicon processes. Covers processes that are more environmentally sensitive. Describes limits of silicon use with respect to high-efficiency solar cells and challenges arising from R&D activities. Defines purity requirements and purification processes of MG-Si. Examines production of solar grade silicon directly from MG-Si.

Download or read book Metal Impurities in Silicon Device Fabrication written by Klaus Graff and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: A discussion of the different mechanisms responsible for contamination together with a survey of their impact on device performance. The author examines the specific properties of main and rare impurities in silicon, as well as the detection methods and requirements in modern technology. Finally, impurity gettering is studied along with modern techniques to determine gettering efficiency. Throughout all of these subjects, the book presents only reliable and up-to-date data so as to provide a thorough review of recent scientific investigations.

Download or read book Interactions of Structural Defects with Metallic Impurities in Multicrystalline Silicon written by and published by . This book was released on 1996 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interactions between structural defects and metallic impurities were studied in multicrystalline silicon for solar cells applications. The objective was to gain insight into the relationship between solar cell processing, metallic impurity behavior and the resultant effect on material/device performance. With an intense synchrotron x-ray source, high sensitivity x-ray fluorescence measurements were utilized to determine impurity distributions with a spatial resolution of ≈ 1[mu]m. Diffusion length mapping and final solar cell characteristics gauged material/device performance. The materials were tested in both the as-grown state and after full solar cell processing. Iron and nickel metal impurities were located at structural defects in as-grown material, while after solar cell processing, both impurities were still observed in low performance regions. These results indicate that multicrystalline silicon solar cell performance is directly related to metal impurities which are not completely removed during typical processing treatments. A discussion of possible mechanisms for this incomplete removal is presented.

Download or read book Solar Energy Update written by and published by . This book was released on 1979 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detecting and Gettering Chromium Impurities in Photovoltaic Crystalline Silicon written by Mallory Ann Jensen and published by . This book was released on 2015 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic (PV) modules provide a source of renewable electricity by harnessing solar energy. Currently, crystalline silicon dominates the PV market with an approximate market share of 90% and record solar cell efficiencies greater than 20%. However, the PV market must decrease the cost to the consumer to maintain growth and meet global electricity demands. Increasing the solar-to-electricity conversion efficiency is one of the most significant cost levers. Transition metal impurities can degrade silicon wafer-based solar cell efficiencies at concentrations as low as 1010 cm3 . By removing interstitial metals from the bulk and/or collecting interstitial metals at heterogeneous nucleation sites, phosphorous diffusion gettering renders them less detrimental in the final solar cell. While they exist for iron, kinetics process simulation tools do not yet exist for chromium, which has higher capture cross-sections for minority carriers and is therefore more detrimental in both p- and n-type materials. In this thesis, I employ synchrotron-based X-ray fluorescence microscopy to study chromium (Cr) distributions in multicrystalline silicon in as-grown material and after two phosphorous diffusion profiles. I complement quantified precipitate size and spatial distribution with interstitial Cr concentration and minority carrier lifetime measurements to provide insight into chromium gettering kinetics and offer suggestions for minimizing the device impacts of chromium. The data presented in this thesis can be used in development of kinetics process simulation tools for chromium gettering. Finally, I describe a new technique for detecting low concentrations of impurities in n- and p-type silicon. The development of high-performance silicon materials, including n-type, necessitates more sensitive impurity detection techniques, capable of measuring interstitial contaminations below 1010 cm-3. I propose the development of a free-carrier absorption-based technique that incorporates a temperature stage. By measuring injection-dependent lifetimes at a wide range of sample temperatures, the identifying parameters of lifetime-limiting defects can be deduced.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sequential Purification and Crystal Growth for the Production of Low Cost Silicon Substrates written by Ming Liaw and published by . This book was released on 1981 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need for low cost silicon for solar cell applications has stimulated the study of direct purification of metallurgical-grade silicon (MG-Si). The technique of sequential purification of molten silicon was investigated. The sequential purification steps included (1) physical separation of insoluble impurities, (2) reactive gas treatment, (3) slagging and (4) impurity redistribution using ingot pulling. The results have shown that the ingot pulling is the most effective step of the purification process. This has been predicted since the majority of metal impurities in silicon have very low segregation coefficients (from 10 -2 to 10 -6). In theory the ingot pulled from the molten silicon will be two to six orders of magnitude lower in the metal concentration than that in the original silicon used for melting. By the same token the pulled ingots can be remelted and repulled. The purity of the silicon can be improved by another 2 to 6 orders of magnitude. The process can be repeated for further purification. The purpose of this paper is to report the purity, structural and electrical characteristics of silicon ingots obtained by various number of crystal pulling.

Download or read book Crystal Growth and Evaluation of Silicon for VLSI and ULSI written by Golla Eranna and published by CRC Press. This book was released on 2014-12-08 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon, as a single-crystal semiconductor, has sparked a revolution in the field of electronics and touched nearly every field of science and technology. Though available abundantly as silica and in various other forms in nature, silicon is difficult to separate from its chemical compounds because of its reactivity. As a solid, silicon is chemically inert and stable, but growing it as a single crystal creates many technological challenges. Crystal Growth and Evaluation of Silicon for VLSI and ULSI is one of the first books to cover the systematic growth of silicon single crystals and the complete evaluation of silicon, from sand to useful wafers for device fabrication. Written for engineers and researchers working in semiconductor fabrication industries, this practical text: Describes different techniques used to grow silicon single crystals Explains how grown single-crystal ingots become a complete silicon wafer for integrated-circuit fabrication Reviews different methods to evaluate silicon wafers to determine suitability for device applications Analyzes silicon wafers in terms of resistivity and impurity concentration mapping Examines the effect of intentional and unintentional impurities Explores the defects found in regular silicon-crystal lattice Discusses silicon wafer preparation for VLSI and ULSI processing Crystal Growth and Evaluation of Silicon for VLSI and ULSI is an essential reference for different approaches to the selection of the basic silicon-containing compound, separation of silicon as metallurgical-grade pure silicon, subsequent purification, single-crystal growth, and defects and evaluation of the deviations within the grown crystals.

Download or read book Energy Research Abstracts written by and published by . This book was released on 1983 with total page 1474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Silicon Based MEMS Materials and Technologies written by Markku Tilli and published by Elsevier. This book was released on 2020-04-17 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Silicon Based MEMS Materials and Technologies, Third Edition is a comprehensive guide to MEMS materials, technologies, and manufacturing with a particular emphasis on silicon as the most important starting material used in MEMS. The book explains the fundamentals, properties (mechanical, electrostatic, optical, etc.), materials selection, preparation, modeling, manufacturing, processing, system integration, measurement, and materials characterization techniques of MEMS structures. The third edition of this book provides an important up-to-date overview of the current and emerging technologies in MEMS making it a key reference for MEMS professionals, engineers, and researchers alike, and at the same time an essential education material for undergraduate and graduate students. - Provides comprehensive overview of leading-edge MEMS manufacturing technologies through the supply chain from silicon ingot growth to device fabrication and integration with sensor/actuator controlling circuits - Explains the properties, manufacturing, processing, measuring and modeling methods of MEMS structures - Reviews the current and future options for hermetic encapsulation and introduces how to utilize wafer level packaging and 3D integration technologies for package cost reduction and performance improvements - Geared towards practical applications presenting several modern MEMS devices including inertial sensors, microphones, pressure sensors and micromirrors

Download or read book Handbook of Photovoltaic Science and Engineering written by Antonio Luque and published by John Wiley & Sons. This book was released on 2011-03-29 with total page 1172 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive, authoritative and widely cited reference on photovoltaic solar energy Fully revised and updated, the Handbook of Photovoltaic Science and Engineering, Second Edition incorporates the substantial technological advances and research developments in photovoltaics since its previous release. All topics relating to the photovoltaic (PV) industry are discussed with contributions by distinguished international experts in the field. Significant new coverage includes: three completely new chapters and six chapters with new authors device structures, processing, and manufacturing options for the three major thin film PV technologies high performance approaches for multijunction, concentrator, and space applications new types of organic polymer and dye-sensitized solar cells economic analysis of various policy options to stimulate PV growth including effect of public and private investment Detailed treatment covers: scientific basis of the photovoltaic effect and solar cell operation the production of solar silicon and of silicon-based solar cells and modules how choice of semiconductor materials and their production influence costs and performance making measurements on solar cells and modules and how to relate results under standardised test conditions to real outdoor performance photovoltaic system installation and operation of components such as inverters and batteries. architectural applications of building-integrated PV Each chapter is structured to be partially accessible to beginners while providing detailed information of the physics and technology for experts. Encompassing a review of past work and the fundamentals in solar electric science, this is a leading reference and invaluable resource for all practitioners, consultants, researchers and students in the PV industry.