Download or read book Structural and Electronic Properties of Nanocrystalline Silicon Thin Film Solar Cells Fabricated by Hot Wire and ECR plasma CVD Techniques written by Kamal Kumar Muthukrishnan and published by . This book was released on 2007 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the second part of this work, we focus primarily on the fabrication and analysis of the electronic properties of solar cells using nanocrystalline intrinsic layers. Apart from measuring the regular I-V characteristics and quantum efficiency, we investigate the critical device properties such as the defect densities in the intrinsic layer and the diffusion length of the minority carriers. By correlating the device results with the structural properties of the films, we are able to conclude that the maximum diffusion length and the minimum defect density can only be attained by depositing the intrinsic layers that are close to the transition to amorphous phase. Although few studies have been done on this transition regime of the deposited films, most of them have concentrated only on the film properties such as conductivity ratios and crystalline fractions. This work clearly describes why transition region is ideal for the fabrication of high efficiency solar cells and what are the critical deposition parameters that are involved in their design.
Download or read book Amorphous and Microcrystalline Silicon Solar Cells Modeling Materials and Device Technology written by Ruud E.I. Schropp and published by Springer. This book was released on 2016-07-18 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amorphous silicon solar cell technology has evolved considerably since the first amorphous silicon solar cells were made at RCA Laboratories in 1974. Scien tists working in a number of laboratories worldwide have developed improved alloys based on hydrogenated amorphous silicon and microcrystalline silicon. Other scientists have developed new methods for growing these thin films while yet others have developed new photovoltaic (PV) device structures with im proved conversion efficiencies. In the last two years, several companies have constructed multi-megawatt manufacturing plants that can produce large-area, multijunction amorphous silicon PV modules. A growing number of people be lieve that thin-film photovoltaics will be integrated into buildings on a large scale in the next few decades and will be able to make a major contribution to the world's energy needs. In this book, Ruud E. I. Schropp and Miro Zeman provide an authoritative overview of the current status of thin film solar cells based on amorphous and microcrystalline silicon. They review the significant developments that have occurred during the evolution of the technology and also discuss the most im portant recent innovations in the deposition of the materials, the understanding of the physics, and the fabrication and modeling of the devices.
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 2013-11-11 with total page 615 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 Nanocrystalline Silicon Solar Cells Deposited Via Pulsed PECVD at 150 c Substrate Temperature written by K. M. Azizur Rahman and published by . This book was released on 2010 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of experiments were carried out to compare the structural and electronic properties of the intrinsic nanocrystalline silicon (nc-Si:H) thin films deposited via continuous wave (cw) and pulsed (p)-PECVD process at 150°C substrate temperature. Working at this temperature allows for the easy transfer of film recipes from glass to plastic substrates in the future. During the p-PECVD process the pulsing frequency was varied from 0.2 to 50 kHz at 50% duty cycle. Approximately 15% drop in the deposition rate was observed for the samples fabricated in p-PECVD compared to cw-PECVD. The optimum crystallinity and photo ([sigma]ph) and dark conductivity ([sigma]D) was observed at 5 kHz pulsing frequency, with ~10% rise in crystallinity and about twofold rise in the [sigma]ph and [sigma]D compared to cw-PECVD. However, for both the cw and p-PECVD nc-Si:H films, the observed [sigma]ph and [sigma]D was one to two orders and three orders of magnitude higher respectively than that reported in literature. The average activation energy (EA) of 0.16 [minpl] 0.01 eV for nc-Si:H films deposited using p-PECVD confirmed the presence of impurities, which led to the observance of the unusually high conductivity values. It is surmised that the films were contaminated by the impurity atoms after they were exposed to air. Following the thin film characterization process, the optimized nc-Si:H film recipes were used for fabricating the absorber layer of thin film solar cells. The cells were characterized for J-V and External Quantum Efficiency (EQE) parameters. The cell active layer fabricated from p-PECVD demonstrated higher power conversion efficiency ([eta]) and a maximum EQE of 1.7 [minpl] 0.06 % and 54.3% respectively, compared to 1.00 [minpl] 0.04 % and 48.6% respectively for cw-PECVD. However, the observed [eta] and EQE of both the cells were lower than a reported nc-Si:H cell fabricated via p-PECVD with similar absorber layer thickness. This was due to the poor Short-circuit Current Density (Jsc), Open-circuit Voltage (Voc), and Fill Factor (FF) of the cw and p-PECVD cells respectively, compared to the reported cell. The low Jsc resulted from the poor photocarrier collection at longer and shorter wavelengths and high series resistance (Rseries). On the other hand, the low Voc stemmed from the low shunt resistance (Rsh). It is inferred that the decrease in the Rsh occurred due to the inadequate electrical isolation of the individual cells and the contact between the n - layer and the front TCO contact at the edge of the p-i-n deposition area. Additionally, the net effect of the high Rseries and the low Rsh led to a decrease in the FF of the cells.
Download or read book Research Highlights written by Iowa State University. Department of Electrical and Computer Engineering and published by . This book was released on 2008 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thin Film Nanocrystalline Silicon Solar Cells Obtained by Hot wire CVD written by Cristóbal Voz Sánchez and published by . This book was released on 2001 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Commencement written by Iowa State University and published by . This book was released on 2006 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Semiconductor Materials and Modelling for Solar Cells written by Z. Pezeshki and published by Materials Research Forum LLC. This book was released on 2021-07-05 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents a comprehensive survey about advanced solar cell technologies. Focus is placed on semiconductor materials, solar cell efficiency, improvements in surface recombination velocity, charge density, high ultraviolet (UV) sensitivity, modeling of solar cells etc. The book references 281 original resources with their direct web links for in-depth reading. Keywords: Solar Cells, Thin Film Solar Cells, Solar Cell Efficiency, Semiconductor Materials, Surface Recombination Velocity, Charge Density, High UV Sensitivity, Heavily-doped Silicon Wafers, Amorphous Semiconductors, Nanocrystalline Semiconductors, Field Effect, Ferroelectric Semiconductors, Solar Cell Modelling.
Download or read book Physics and Technology of Amorphous Crystalline Heterostructure Silicon Solar Cells written by Wilfried G. J. H. M. van Sark and published by Springer Science & Business Media. This book was released on 2011-11-16 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.
Download or read book Next Generation Multilayer Graded Bandgap Solar Cells written by A. A. Ojo and published by Springer. This book was released on 2018-08-16 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will guide Photovoltaics researchers in a new way of thinking about harvesting light energy from all wavelengths of the solar spectrum. It closes the gap between general solar cells books and photovoltaics journal articles, by focusing on the latest developments in our understanding of solid-state device physics. The material presented is experimental and based on II-VI thin-film materials, mainly CdTe-based solar cells. The authors describe the use of new device design, based on multilayer graded bandgap configuration, using CdTe-based solar cells. The authors also explain how the photo-generated currents can be enhanced using multi-step charge carrier production. The possibility of fabricating these devices using low-cost and scalable electroplating is demonstrated. The value of electroplating for large area electronic devices such as PV solar panels, display devices and nano-technology devices are also demonstrated. By enabling new understanding of the engineering of electroplated semiconductor materials and providing an overview of the semiconductor physics and technology, this practical book is ideal to guide researchers, engineers, and manufacturers on future solar cell device designs and fabrications. Discusses in detail the processes of growths, treatments, solar cell device fabrication and solid state physics, improving readers’ understanding of fundamental solid state physics; Enables future improvements in CdTe-based device efficiency; Explains the significance of defects in deposited semiconductor materials and interfaces that affect the material properties and resulting device performance.
Download or read book Correlation of Structural and Electronic Properties with Solar Cell Efficiency for Amorphous Silicon Deposited at Increasing Growth Rates written by B. P. Nelson and published by . This book was released on 2003 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper details the effects of increasing the growth rate of hydrogenated amorphous silicon (a-Si:H), deposited by dc plasma chemical vapor deposition, on the structural and electronic properties of the material in comparison with the performance of solar cells incorporating such layers. The hydrogen content exhibits the strongest correlation with the solar cell efficiency. The defect density measured by two different techniques, correlate poorly but when measured by a third technique, correlates well. On the other hand, the Urbach tail slope correlated well when measured by two different techniques but poorly when measured by a third one.
Download or read book Characterization of Electrical Properties of Thin film Solar Cells written by Rasha A. Awni and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic (PV) solar cells have attracted great attention because of the demand for low cost renewable energy sources. Detailed information on electronic properties, such as doping, defects, gap states...etc, must be fully understood to develop the technology of solar cells. Here, we report the fundamental electronic properties of two distinct materials systems, one is based on polycrystalline cadmium telluride (CdTe) and the other is lead-halide perovskite solar cells. This investigation provides useful information to understand the fundamental nature of single junction solar cell device and material. First, we investigate the impact of back surface treatment method for cadmium sulfide (CdS)/CdTe solar cells using hydroiodic acid (HI) etching to provide an appropriate electrical back contact. The structural properties of CdTe films and electrical properties of the CdTe absorber and interfaces are characterized. Using capacitance-based techniques with the support of current-voltage measurements, we show that the barrier height of the back contact is reduced, apparent doping concentration is increased, and a defect level at 0.409eV is eliminated after the HI-treatment. More importantly, the CdTe device performance is improved. This improvement is still limited by many factors. One factor is the device window layer that limits the current generation. Therefore, we replaced CdS layer by wide bandgap material, ZnMgO (ZMO). We noticed that the electrical properties of CdS/CdTe and ZMO/CdTe solar cells depend on both buffer material and the fabrication atmosphere. Using capacitance spectroscopy-based techniques, we show that CdS/CdTe solar cells have negligible front contact barriers regardless of the fabrication atmospher, while ZMO/CdTe devices show obvious front barriers are dependent on the fabrication atmosphere. Both CdS/CdTe and ZMO/CdTe solar cells have significant back contact barriers. Additionally, we find that the energy level of defects in CdS/CdTe cells is shallower than in ZMO/CdTe cells. These results provide deep insights for understanding and optimizing the performance of CdTe thin-film solar cells. Then, we explored the electrical properties of halide perovskite solar cells (PSCs) that can be deduced by capacitance-based techniques, such as defect activation energy and density, carrier concentration, and dielectric constant. However, we find that these techniques cannot reliably be used to characterize the properties of the defects in the perovskite layer or at its interface. We find that the high-frequency capacitance signature is due to the response of charge carriers in the hole-transport layer (HTL), not in the perovskite layer. In HTL-free PSCs, from the capacitance spectra at high-frequency, the geometric capacitance can be determined and can be used to calculate the dielectric constant of perovskite layers. We also find an overlapping effect with the charge transport layers at the low-frequency capacitance signature in planner PSCs, thus, it cannot be used to analyze the defect properties. However, in the inverted structure PSCs, the low-frequency capacitance signature can be used to calculate the activation energy of the ionic conductivity of the perovskite layer.
Download or read book Proceedings of the National Workshop on Low Cost Polycrystalline Silicon Solar Cells May 18 19 1976 Southern Methodist University Dallas Texas written by Ting L. Chu and published by . This book was released on 1976 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thin Film Silicon Solar Cells written by Arvind Victor Shah and published by CRC Press. This book was released on 2010-08-19 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic technology has now developed to the extent that it is close to fulfilling the vision of a "solar-energy world," as devices based on this technology are becoming efficient, low-cost and durable. This book provides a comprehensive treatment of thin-film silicon, a prevalent PV material, in terms of its semiconductor nature, startin
Download or read book Epitaxial Thin Film Silicon Solar Cells Fabricated by Hot Wire Chemical Vapor Deposition Below 750 deg C written by and published by . This book was released on 2009 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on fabricating film c-Si solar cells on Si wafer templates by hot-wire chemical vapor deposition. These devices, grown at glass-compatible temperatures 750.deg. C, demonstrate open-circuit voltages 500 mV and efficiencies> 5%.
Download or read book Crystalline Silicon Thin Film Growth by ECR Plasma CVD for Solar Cells written by Licai Wang and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystalline Silicon Solar Cells written by Adolf Goetzberger and published by Wiley. This book was released on 1998-04-08 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: As environmental concerns escalate, solar power is increasingly seen as an attractive alternative energy source. Crystalline Silicon Solar Cells addresses the practical and theoretical issues fundamental to the viable conversion of sunlight into electricity. Written by three internationally renowned experts, this valuable reference profits from results and experience gained from research at the Fraunhofer Institute for Solar Energy Systems. Features include: Introduction to the principles of photovoltaics, providing a grounding in semiconductor physics for the novice reader Special emphasis on the methods of attaining high efficiency and thereby cost-effective solar power Examination of the physics, design and technology of crystalline silicon solar cells, in particular thin film cells Survey of a selection of alternative cell types equipping the reader with a complete overview Detailed description of measuring and analysis techniques to facilitate determining physical semiconductor and solar cell parameters Accessible to those with a basic knowledge of physics and mathematics, this is an excellent introductory book for students studying solid state and semiconductor physics. All those working in photovoltaic development and production will find Crystalline Silicon Solar Cells an indispensable resource.
