Download or read book Physical Models of Thin Film Polycrystalline Solar Cells Based on Measured Grain boundary and Electronic parameter Properties Quarterly Report written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells fabricated on polycrystalline silicon, either bulk or thin-film, can potentially be cost-effective when used in terrestrial photovoltaic energy-conversion systems. To achieve this goal, the polysilicon cell efficiency must be increased considerably from its present values. A severe limitation to the cell efficiency is due to the grain boundaries and their influence on carrier recombination. To remove this limitation, an understanding of the fundamental physics underlying the effects of the grain boundaries on cell performance is helpful. This fundamental physics is discussed, and models are developed for recombination currents in polysilicon pn-junction solar cells. Several analytic approximations, suggested by physical insight, are used and checked ultimately for self-consistency with the results of the analysis. The models are defined such that their parameters can be related directly to measurements, and the models are hence useful in interpreting experimental results. They also can be used to study, in a systematic way, cell-design modifications to improve the efficiency, e.g., grain-boundary passivation techniques.
Download or read book Physical Models of Thin Film Polycrystalline Solar Cells Based on Measured Grain boundary and Electronic parameter Properties written by F. A Lindholm and published by . This book was released on 1979 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physical Models of Thin Film Polycrystalline Solar Cells Based on Measured Grain boundary and Electronic parameter Properties Final Report September 18 1978 December 31 1979 written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research has sought the following: to identify and characterize the basic photovoltaic mechanisms that govern the conversion efficiency of polycrystalline thin-film solar cells; to experimentally determine the electronic parameters related to these photovoltaic mechanisms; and to relate these mechanisms and parameters to the conversion efficiency through theoretical physical models developed for engineering design. These objectives are all intimately related. The emphasis of the work has been on polysilicon, although it is building a foundation of understanding useful for similar research in the future on other thin-film materials. Progress is reported. (WHK).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 772 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 1986 with total page 600 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 1980 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Department of Energy Solar Energy Objectives written by United States. Department of Energy and published by . This book was released on 1980 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photovoltaic Energy Systems written by and published by . This book was released on 1980 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy a Continuing Bibliography with Indexes written by and published by . This book was released on 1978 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thin Film Solar Cells written by K.L. Chopra and published by Springer Science & Business Media. This book was released on 1983-07-31 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: "You, 0 Sun, are the eye of the world You are the soul of all embodied beings You are the source of all creatures You are the discipline of all engaged in work" - Translated from Mahabharata 3rd Century BC Today, energy is the lifeline and status symbol of "civilized" societies. All nations have therefore embarked upon Research and Development pro grams of varying magnitudes to explore and effectively utilize renewable sources of energy. Albeit a low-grade energy with large temporal and spatial variations, solar energy is abundant, cheap, clean, and renewable, and thus presents a very attractive alternative source. The direct conver sion of solar energy to electricity (photovoltaic effect) via devices called solar cells has already become an established frontier area of science and technology. Born out of necessity for remote area applications, the first commercially manufactured solar cells - single-crystal silicon and thin film CdS/Cu2S - were available well over 20 years ago. Indeed, all space vehicles today are powered by silicon solar cells. But large-scale terrestrial applications of solar cells still await major breakthroughs in terms of discovering new and radical concepts in solar cell device structures, utilizing relatively more abundant, cheap, and even exotic materials, and inventing simpler and less energy intensive fabrication processes. No doubt, this extraordinary challenge in R/D has led to a virtual explosion of activities in the field of photovoltaics in the last several years.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1982-02 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Energy Objectives Calendar Year 1980 written by United States. Department of Energy and published by . This book was released on 1980 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Study of Grain Boundaries in Polycrystalline Thin film Solar Cells written by Bingrui Joel Li and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon is one of the most studied semiconductor materials with techniques to control and manipulate its properties well established by the integrated circuit (IC) industry. While silicon wafer-based technology constitutes about 85% of the photovoltaics (PV) market, there are compelling reasons to develop thin-film solar cells. These include potential material cost and energy savings achievable with thin absorber layers of direct band-gap thin film materials, and the potential for incorporation of thin film PV onto inexpensive, flexible, or building material substrates, which opens up the possibility of new applications. Given the success of silicon wafer-based solar cells in the PV market, crystalline silicon on glass is a natural choice for thin-film PV technology. However, the efficiency of this technology is still too low to compete in the PV market. In fact, its record efficiency is only 10.5% which was achieved by CSG Solar. In order to boost the efficiency of this technology, we explore the use of ion-beam assisted deposition (IBAD) to create biaxially-textured silicon films which can potentially have less defects at the grain boundaries. Experimentally, we have fabricated an operational biaxially-textured silicon solar cell whose Voc is likely to have been affected by intra-grain defects as shown by our transmission electron microscopy (TEM) image. In order to investigate the interplay between grain boundary and intra-grain defects on solar cell performance and determine the potential benefits of developing biaxially-textured film solar cells, I used Synopsys' two-dimensional technology computer-aided design (TCAD) Sentaurus simulation tool. In general, the simulations found that biaxially-textured silicon solar cells improve solar cell efficiencies but there is small improvement for devices that have both large grains and low intra-grain carrier lifetime. Among the various thin-film technologies, CdTe and Cu(In, Ga)(S, Se)2 (CIGSSe), dominate the thin-film PV market. However in recent years, the photovoltaic community has seen growing interest in CZTS-based thin-film solar cells which include Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) and Cu2ZnSn(S, Se)4 (CZTSSe) solar cells. This is driven by their potential to replace Cu(In, Ga)Se2 (CIGSe) and CdTe solar cells which face material scarcity, toxicity and market acceptance issues. In polycrystalline CIGSe-based (CIGSe, CISe, CuGaSe2 (CGSe)) and CdTe solar cells, grain boundaries do not seem to affect solar cell efficiency as much. In fact, some studies have identified grain boundaries as the source of high efficiency in polycrystalline CIGSe-based and CdTe solar cells. CIGSe-based and CZTS-based films are similar in terms of growth methods, optoelectronic and crystallographic properties. Because of these similarities and the benign nature of grain boundaries in CIGSe-based and CdTe films, it would be useful to examine the properties of grain boundaries in these materials. Using scanning Kelvin probe microscopy (SKPM) and conductive atomic force microscopy (C-AFM) techniques, I investigated the electronic properties of grain boundaries in CIGSe, CZTS and CZTSSe solar cells. SKPM measurements carried out in this work reveal a higher positive surface potential at the grain boundaries as compared to the grain while C-AFM measurements show higher current flow in the vicinity of the grain boundaries. These two measurement results are similar to those obtained for high quality CIGSe and CdTe and together they demonstrate the enhanced minority carrier collection taking place at the grain boundaries of CZTS and CZTSSe. Although SKPM measurement are susceptible to topographical and geometric effects, we believe that this effect is not dominating in our measurements as topography and surface potential profile lines are not exact mirror images of one another and regions of similar height have different potentials and vice versa. Nonetheless, I used a technique that involves photoreduction of AgNO3 to provide convincing evidence that our SKPM result is not a result of experimental artifacts but is truly indicative of the higher positive potential at the grain boundary. Having benign or beneficial grain boundaries have been found to be essential for achieving high efficiencies in polycrystalline CIGSe and CdTe solar cells. In my investigation, I found that high efficiency CZTS and CZTSSe solar cells have similar grain boundary electronic properties as high efficiency CIGSe and CdTe solar cells. As such, it might be possible for CZTS and CZTSSe solar cells to achieve similar high efficiencies as CIGSe and CdTe solar cells if other defects (intra-grain, surface and interfacial) are not limiting efficiencies.
Download or read book Polycrystalline And Amorphous Thin Films And Devices written by Lawrence Kazmerski and published by Elsevier. This book was released on 2012-12-02 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycrystalline and Amorphous Thin Films and Devices is a compilation of papers that discusses the electronic, optical, and physical properties of thin material layers and films. This compilation reviews the different applications of thin films of various materials used as protective and optical coatings, thermal transfer layers, and selective membranes from submicron- area VLSI memory units to large-area energy conservation devices. Some papers discuss the basic properties, such as growth, structure, electrical, and optical mechanisms that are encountered in amorphous and polycrystalline thin semiconductor films. For example, experiments on electronic structure of dislocations have led to a model for the intrinsic properties of grain boundaries in polycrystalline semiconductor thin films that can have an impact on the designs of high-efficiency, thin-film solar cells. Other papers review the problems encountered in these thin layers in active semiconductor devices and passive technologies. Techniques in film growth and control variables of source, substrate temperature, and substrate properties will determine the successful performance of the devices installed with these thin film layers. This compilation can prove valuable for chemists, materials engineers, industrial technologists, and researchers in thin-film technology.
Download or read book Thin Films Photovoltaics written by Beddiaf Zaidi and published by BoD – Books on Demand. This book was released on 2022-02-23 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film photovoltaic-based solar modules produce power at a low cost per watt. They are ideal candidates for large-scale solar farms as well as building-integrated photovoltaic applications. They can generate consistent power, not only at elevated temperatures but also on cloudy, overcast days and at low sun angles.Thin film photovoltaics are second-generation solar cells produced by depositing one or more thin layers, or thin films, of photosensitive material on a suitable substrate such as glass, polymer, or metal. Thin film solar cells are based on various materials such as cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), and amorphous thin film silicon (a-Si, TF-Si) are commercially used in several conventional and advanced technologies.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1982 with total page 1012 pages. Available in PDF, EPUB and Kindle. Book excerpt:
