Download or read book Development and Characterization of Sputtered Films for Applications in CdS CdTe Solar Cells written by Xu Wang and published by . This book was released on 1998 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopic Ellipsometry Studies of CdS CdTe Thin Films and Photovoltaic Devices written by Michelle Nicole Sestak and published by . This book was released on 2012 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the demand for clean, renewable energy sources increases, the development of high efficiency, low cost photovoltaic devices from thin films becomes increasingly important. Spectroscopic ellipsometry is a promising tool for the characterization and investigation of thin film photovoltaic devices and the component materials from which they are made. This tool can be applied either in-situ and in real-time using high speed multichannel instruments, or ex-situ using slower wavelength-by-wavelength scanning instruments. Spectroscopic ellipsometry is promising for use in thin film photovoltaics because it provides the thicknesses of the individual layers and their optical properties, which in turn provide insights into the light collection required for photocurrent generation. Advanced forms of ellipsometry include (i) ex-situ mapping spectroscopic ellipsometry with a multichannel ellipsometer, which provides information on thickness and optical property non-uniformities over large areas of a coated substrate, and (ii) real-time spectroscopic ellipsometry with similar high speed instrumentation, which provides information on thin film nucleation, coalescence, and growth, as well as changes in the structure of the material over time. Both advanced forms of ellipsometry have been applied in this Dissertation to analyze thin films with applications in photovoltaics. In this Dissertation research, ex-situ mapping ellipsometry has been used to study Au nanoparticle thin films. These films are useful because they can be integrated into solar cells to promote light trapping within the absorber layers, and hence, increase the overall efficiency of the cells. Studying these films with mapping spectroscopic ellipsometry provides a means for determining thickness uniformity over large areas of the sample for scale-up of the deposition processes. The uniformity of other parameters of the Au nanoparticle films such as the plasmon resonance band energy and its broadening are also critical, as these can be optimized to ensure maximum coupling of light into the solar cell absorber layer. In addition, the advanced methods of real-time spectroscopic ellipsometry (RTSE) have been used to characterize a series of CdTe thin films deposited via magnetron sputtering. In this case, analysis of RTSE data provides information on the nucleation, coalescence, and growth of thin films under different deposition conditions. The time evolution of the thicknesses of the nucleating, bulk-like, and surface roughness layers provide an indication of the growth mode, and enable the distinction of initial clustering from initial layer-by-layer growth. The growth mode shows consistent trends with the deposition parameters. In addition, RTSE provides accurate complex dielectric functions of the growing films, since the films are free from oxidation, and surface roughness can be taken into account in the analysis. From the dielectric functions, information on the void fraction, electron mean free path, and stress in these films can be obtained. Also presented in this Dissertation are the results of a study of CdTe solar cells deposited by magnetron sputtering at varying argon pressures and for varying CdCl2 treatment times. These cells were studied through analyses of the current-voltage (J-V) curves and through comparisons of J-V deduced parameters for cells of varying pressures and treatment times. In two independent series of depositions, it was surprising that samples deposited at a specific argon pressure (10 mTorr) performed the best. This optimum pressure separates a regime at low pressures in which the sputtered species experience no collisions upon transit to the substrate, and a regime at high pressures in which the sputtered species experience multiple collisions and are nearly thermalized. Also obtained in this research were quantum efficiency curves for the best performing cells. The measured quantum efficiency for a 10 mTorr sample could be simulated using parameters obtained from ex-situ spectroscopic ellipsometry measurements. Assumptions made in this simulation identified the nature of current losses in the solar cells. Finally, this Dissertation presents a study of a new flexible CdTe solar cell configuration fabricated via an advanced substrate transfer process. In this process, the solar cell is deposited on a temporary superstrate of aluminum foil and transferred to a permanent polymer substrate. This process is used since flexible polymers cannot withstand the deposition temperatures used for the fabrication of CdTe solar cells via the industrial processes of vapor transport deposition and close space sublimation. This novel process has been shown previously to be useful for production of a-Si:H solar modules, and this Dissertation research showed for the first time that it may also be useful for CdTe solar cells, even though the process requires further optimization to reach commercializable efficiencies.
Download or read book Solar Cells and Modules written by Arvind Shah and published by Springer Nature. This book was released on 2020-07-16 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive introduction to the field of photovoltaic (PV) solar cells and modules. In thirteen chapters, it addresses a wide range of topics including the spectrum of light received by PV devices, the basic functioning of a solar cell, and the physical factors limiting the efficiency of solar cells. It places particular emphasis on crystalline silicon solar cells and modules, which constitute today more than 90 % of all modules sold worldwide. Describing in great detail both the manufacturing process and resulting module performance, the book also touches on the newest developments in this sector, such as Tunnel Oxide Passivated Contact (TOPCON) and heterojunction modules, while dedicating a major chapter to general questions of module design and fabrication. Overall, it presents the essential theoretical and practical concepts of PV solar cells and modules in an easy-to-understand manner and discusses current challenges facing the global research and development community.
Download or read book SERI Photovoltaic Advanced Research and Development Bibliography 1982 1985 written by and published by . This book was released on 1986 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Energy Update written by and published by . This book was released on 1984 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coatings and Thin Film Technologies written by Jaime Andres Perez Taborda and published by BoD – Books on Demand. This book was released on 2019-01-03 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of coatings and thin-film technologies is rapidly advancing to keep up with new uses for semiconductor, optical, tribological, thermoelectric, solar, security, and smart sensing applications, among others. In this sense, thin-film coatings and structures are increasingly sophisticated with more specific properties, new geometries, large areas, the use of heterogeneous materials and flexible and rigid coating substrates to produce thin-film structures with improved performance and properties in response to new challenges that the industry presents. This book aims to provide the reader with a complete overview of the current state of applications and developments in thin-film technology, discussing applications, health and safety in thin films, and presenting reviews and experimental results of recognized experts in the area of coatings and thin-film technologies.
Download or read book Surface Chemical Analysis written by and published by . This book was released on 2010 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals Of Solar Cells written by Alan Fahrenbruch and published by Elsevier. This book was released on 2012-12-02 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Solar Cells: Photovoltaic Solar Energy Conversion provides an introduction to the fundamental physical principles of solar cells. It aims to promote the expansion of solar photovoltaics from relatively small and specialized use to a large-scale contribution to energy supply. The book begins with a review of basic concepts such as the source of energy, the role of photovoltaic conversion, the development of photovoltaic cells, and sequence of phenomena involved in solar power generation. This is followed by separate chapters on each of the processes that take place in solar cell. These include solar input; properties of semiconductors; recombination and the flow of photogenerated carriers; charge separation and the characteristics of junction barriers; and calculation of solar efficiency. Subsequent chapters deal with the operation of specific solar cell devices such as a single-crystal homojunction (Si); a single-crystal-heterojunction/buried-homojunction (AlGaAs/GaAs); and a polycrystalline, thin-film cell (CuxS/CdS). This book is intended for upper-level graduate students who have a reasonably good understanding of solid state physics and for scientists and engineers involved in research and development of solar cells.
Download or read book Issues in the Development of All sputtered ZnO CdS CdTe Flexible Solar Cells written by Anthony Clark Vasko and published by . This book was released on 2009 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cadmium telluride (CdTe) solar cells are traditionally made on glass in a superstrate configuration, taking advantage of the transparency and mechanical rigidity of glass, as well as the ability to form the back contact last. However, there are advantages to fabricating solar cells on flexible substrates such as plastic sheets. Advantages include high specific powers (power generated per mass of the device) for low weight applications, the possibility for continuous roll-to-roll manufacturing suitable for industry, and the opportunity to place solar devices on objects and structures that are not necessarily flat. We have fabricated various flexible CdTe devices through sputter deposition, using aluminum doped zinc oxide (AZO) as a transparent conducting oxide (TCO) top contact. Early devices, made by naively applying fabrication techniques used with glass cells, had poor performance. This inspired several investigations. Traditional simple heuristic analysis of solar cell current-voltage curves assumes the cell is reasonably performing and that series and shunt resistance losses are small. This was not true for our early cells, inspiring us to derive a simple model for very poor cells. Early cells showed significant losses due to both series and shunt resistance. Series resistance losses in flexible cells inspired us to investigate more deeply series resistance losses in general, resulting in a fairly simple model that relates fill factor losses, in dot cells made in a typical geometry, to TCO sheet resistance. This model was confirmed by experiment. Series resistance losses also led to futher investigation of AZO properties. We have found that AZO sheet resistance increases during cell fabrication, but a model that is supported by experiment indicates that the resistivity change is limited to a finite thickness of material. This allows fabrication of AZO which remains of good sheet resistance throughout the fabrication process. Shunt resistance losses inspired a study of highly resistive and transparent (HRT) zinc oxide made by reactive sputtering with oxygen, which can be used as a buffer for shunts. Data on resisitivity as a function of oxygen in the sputter gas is given when using doped and undoped zinc oxygen sputter targets. Calculations on theoretical effects of such buffer layers are also presented. A high temperature cadmium chloride (CdCl2) treatment is needed to create high efficiency CdTe cells. This can be a difficult step for flexible cells, as it can lead to CdTe film delamination. We have optimized a treatment for flexible cells and found that conditions, different from those which are optimal for cells on glass, allows high performance with no delamination. Understanding of these issues allowed progress in the performance of our cells fabricated on flexible substrates. Ultimately, we have fabricated a flexible CdTe cell with efficiency of 10.5%. This efficiency is, to our knowledge, the best of any flexible CdTe cell which uses zinc oxide as a transparent conducting oxide. The performance of these cells also compares favorably to the best overall flexible CdTe cells.
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 Energy Research Abstracts written by and published by . This book was released on 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Advances in Thin Film Photovoltaics written by Udai P. Singh and published by Springer Nature. This book was released on 2022-09-02 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides recent development in thin-film solar cells (TFSC). TFSC have proven the promising approach for terrestrial and space photovoltaics. TFSC have the potential to change the device design and produce high efficiency devices on rigid/flexible substrates with significantly low manufacturing cost. TFSC have several advantages in manufacturing compared to traditional crystalline Si-solar cells like less requirement of materials, can be prepared with earth’s abundant materials, less processing steps, easy to dispose, etc. Several universities/research institutes/industry in India and abroad are involved in the research area of thin-film solar cells. The book helps the readers to find the details about different thin-film technologies and its advancement at one place. Each chapter covers properties of materials, its suitability for PV applications, simple manufacturing processes and recent and past literature survey. The issues related to the development of high efficiency TFSC devices over large area and its commercial and future prospects are discussed.
Download or read book McEvoy s Handbook of Photovoltaics written by Soteris Kalogirou and published by Academic Press. This book was released on 2017-08-24 with total page 1341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Handbook of Photovoltaics, Third Edition, is a 'benchmark' publication for those involved in the design, manufacture and use of these devices. This fully revised handbook includes brand new sections on smart grids, net metering and the modeling of photovoltaic systems, as well as fully revised content on developments in photovoltaic applications, the economics of PV manufacturing and updated chapters on solar cell function, raw materials, photovoltaic standards, calibration and testing, all with new examples and case studies. The editor has assembled internationally-respected contributors from industry and academia around the world to make this a truly global reference. It is essential reading for electrical engineers, designers of systems, installers, architects, policymakers and physicists working with photovoltaics. - Presents a cast of international experts from industry and academia to ensure the highest quality information from multiple stakeholder perspectives - Covers all things photovoltaics, from the principles of solar cell function and their raw materials, to the installation and design of full photovoltaic systems - Includes case studies, practical examples, and reports on the latest advances and worldwide applications
Download or read book Synthesis and Characterization of Pure LaS and Growth of CdS Thin film by RF Sputtering written by Hai Tang and published by . This book was released on 2000 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Characterization Techniques for Thin Film Solar Cells written by Daniel Abou-Ras and published by John Wiley & Sons. This book was released on 2016-07-13 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on advanced characterization methods for thin-film solar cells that have proven their relevance both for academic and corporate photovoltaic research and development. After an introduction to thin-film photovoltaics, highly experienced experts report on device and materials characterization methods such as electroluminescence analysis, capacitance spectroscopy, and various microscopy methods. In the final part of the book simulation techniques are presented which are used for ab-initio calculations of relevant semiconductors and for device simulations in 1D, 2D and 3D. Building on a proven concept, this new edition also covers thermography, transient optoelectronic methods, and absorption and photocurrent spectroscopy.
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1979 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt:
