Download or read book Silicon Surface and Heterojunction Interface Passivation Studies by Lifetime Measurements written by and published by . This book was released on 2003 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report two investigations conducted by using photoconductivity decay lifetime measurement. The first is crystalline silicon (c-Si) surface passivation using quinhydrone/methanol (QM) for bulk minority-carrier lifetime measurement. QM shows great promise as a substitute for iodine-based solutions because of its superior stability and minimized surface-recombination velocity in silicon. The second is interface passivation in an amorphous silicon (a-Si)/c-Si heterojunction structure as a parallel effort to develop and optimize heterojunction c-Si solar cells by hot-wire chemical vapor deposition (HWCVD). A thin buffer layer inserted between the a-Si and the c-Si substrate has been found to be much more effective than a directly deposited a-Si/c-Si interface in reducing the interface recombination velocity.
Download or read book Toward Better Understanding and Improved Performance of Silicon Heterojunction Solar Cells written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The double-sided silicon heterojunction (SHJ) solar cell is more appropriate for n-type crystal silicon (c-Si) wafers than for p-type c-Si wafers because there is a larger band offset to the valence band edge of hydrogenated amorphous silicon than to the conduction band edge. Thin intrinsic and doped hydrogenated amorphous silicon (a Si:H) double layers by hot-wire chemical vapor deposition (HWCVD) are investigated as passivation layers, emitters, and back-surface-field (BSF) contacts to both p- and n-type wafers. Passivation quality is studied by characterizing the SHJ solar cells and by photoconductive decay (PCD) minority-carrier lifetime measurements. The crystal-amorphous heterointerface is studied with real-time spectroscopic ellipsometry (RTSE) and high-resolution transmission electron microscopy (HRTEM) to detect phase change and material evolution, with a focus on better understanding the factors determining passivation effectiveness. A common feature in effective passivation, emitter, and BSF layers is immediate a-Si:H deposition and an abrupt and flat interface to the c-Si substrate. In this case, good wafer passivation or an excellent heterojunction is obtained, with a low interface recombination velocity (S) or a high open-circuit voltage (Voc). Voc greater than 640 mV, S less than 15 cm/sec, and efficiency of 14.8% have been achieved on polished p type Czochralski-grown (CZ) Si wafers. Collaboration between NREL and Georgia Tech resulted in a 15.7%-efficient HWCVD-deposited SHJ cell on non-textured FZ-Si with a screen-printed Al back surface field (BSF), the highest reported HWCVD SHJ cell. Collaboration between NREL and SunPower demonstrated that HWCVD a-Si:H passivation can be better than the conventional oxides, with a low surface recombination velocity of 42 cm/sec on textured n-type FZ-Si.
Download or read book Characterization of Surface Passivation of Crystalline Silicon by Hydrogenated Amorphous Silicon Using Photocarrier Radiometry written by Keith R. Leong and published by . This book was released on 2006 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the silicon heterojunction solar cell, the crystalline silicon (c-Si) surface forms an interface with hydrogenated amorphous silicon (a-Si:H). This thesis reports on the development and evaluation of surface passivation schemes of c-Si with a-Si:H. The passivation consists of a three step process: cleaning of the c-Si surface, etching of the native oxide, and deposition the a-Si:H layer. Evaluation of the passivation schemes was conducted by recombination lifetime measurements using Photocarrier Radiometry (PCR). The SPM, RCA SC1, and SC2 cleaning sequence, followed by either buffered HF, and the growth of the a-Si:H film produced the highest PCR characteristic lifetime (80.9 mus). In the high injection regime, lifetime from PCR correlated with that from mu-PCD within a factor of 1.2 to 2.5. PCR laser annealing of the a-Si:H was observed for laser intensities at or above 2.9 suns. ToF-SIMS measurements identified Na, K, Ca, O, and SiO2 contaminants at the interface.
Download or read book Amorphous Silicon Crystalline Silicon Heterojunction Solar Cells written by Wolfgang Rainer Fahrner and published by Springer Science & Business Media. This book was released on 2013-04-23 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amorphous Silicon/Crystalline Silicon Solar Cells deals with some typical properties of heterojunction solar cells, such as their history, the properties and the challenges of the cells, some important measurement tools, some simulation programs and a brief survey of the state of the art, aiming to provide an initial framework in this field and serve as a ready reference for all those interested in the subject. This book helps to “fill in the blanks” on heterojunction solar cells. Readers will receive a comprehensive overview of the principles, structures, processing techniques and the current developmental states of the devices. Prof. Dr. Wolfgang R. Fahrner is a professor at the University of Hagen, Germany and Nanchang University, China.
Download or read book Heterojunction Solar Cells a Si c Si written by Thomas Mueller and published by Logos Verlag Berlin GmbH. This book was released on 2009 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main focus of the present work is related to the optimization of heterojunction solar cells. The key roles in obtaining high efficient heterojunction solar cells are mainly the plasma enhanced chemical vapor deposition of very low defect layers, and the sufficient surface passivation of all interfaces. In heterojunction solar cells, the a-Si: H/c-Si hetero-interface is of significant importance, since the hetero-interface characteristics directly affect the junction properties and thus solar cell efficiency. In this work, the deposition and film properties of various hydrogenated amorphous silicon alloys, such as a-SiC: H, a-SiO_x: H, and muc-Si: H (standard a-Si: H is used as reference), are employed. Special attention is paid to (i) the front and back surface passivation of the bulk material by high-quality wide-gap amorphous silicon suboxides (a-SiO_x: H), and (ii) the influence of wide-gap high-quality a-Si- and muc-Si-based alloys for use as emitter and back-surface-
Download or read book Silicon Heterojunction Solar Cells written by W.R. Fahrner and published by Trans Tech Publications Ltd. This book was released on 2006-08-15 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world of today must face up to two contradictory energy problems: on the one hand, there is the sharply growing consumer demand in countries such as China and India. On the other hand, natural resources are dwindling. Moreover, many of those countries which still possess substantial gas and oil supplies are politically unstable. As a result, renewable natural energy sources have received great attention. Among these, solar-cell technology is one of the most promising candidates. However, there still remains the problem of the manufacturing costs of such cells. Many attempts have been made to reduce the production costs of conventional solar cells (manufactured from monocrystalline silicon using diffusion methods) by instead using cheaper grades of silicon, and simpler pn-junction fabrication. That is the hero of this book; the heterojunction solar cell.
Download or read book Photovoltaic Materials and Manufacturing Issues written by and published by . This book was released on 2009 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Semiconductor Devices written by R. K. Sharma and published by Springer. This book was released on 2019-01-31 with total page 1299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book disseminates the current knowledge of semiconductor physics and its applications across the scientific community. It is based on a biennial workshop that provides the participating research groups with a stimulating platform for interaction and collaboration with colleagues from the same scientific community. The book discusses the latest developments in the field of III-nitrides; materials & devices, compound semiconductors, VLSI technology, optoelectronics, sensors, photovoltaics, crystal growth, epitaxy and characterization, graphene and other 2D materials and organic semiconductors.
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 Surface and Interface Studies of Oxygen on Silicon III V Heterojunctions Schottky Barriers written by Charles Michael Garner and published by . This book was released on 1978 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Detailed Investigation of Surface Passivation Methods for Lifetime Measurements on Silicon Wafers written by Kevin L. Pollock and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of SHJ Silicon HeteroJunction Cells Heterogeneities on Their Performances written by Valentin Giglia and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In a context where commercially available monocrystalline silicon substrates allow charge carrier lifetimes of several milliseconds, the passivation state of the silicon surfaces in silicon heterojunction solar cells comes to the forefront for improving the performance of these industrially produced cells. First, the passivation defects of the front and back surfaces of the device have been studied by combining simulations (Silvaco) and experiments. This allowed the understanding and quantification of the physical phenomena involved in the losses associated with passivation defects. The influence of the variation of the defect properties was then revealed under standard test conditions as well as under different illuminations and operating temperatures in order to reproduce the real operating conditions of the cells. Furthermore, it is known that the passivation quality of the cell edges is lower compared to the front and back surfaces. This is all the more important with the rise of photovoltaic modules with cut cells. These cells being smaller, the current flowing through them, and therefore the associated resistive losses, are reduced. In these cells, edges are generated by the cuts and the ratio perimeter/surface being high, the edge effects are exacerbated. In a second step, a novel simulation code was developed to study these effects on the performance of the cells. This allowed to understand and quantify the phenomena involved in the edge losses of whole and cut cells. In particular, the In particular, the performance of a cell was related to the speed of recombination at its edges, regardless of the size and geometry of the cell. For each of these studies, practical recommendations for the reduction of these losses on industrially produced cells have been formulated.
Download or read book Excellent Surface Passivation for High Efficiency C Si Solar Cells written by Sara Bakhshi and published by . This book was released on 2018 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor surface clean is sometimes perceived as costly but long recognized as pivotal in determining the final semiconductor device performance and yield. In this contribution, we investigated the effectiveness of crystalline silicon surface cleaning by a simple UV-ozone process in comparison to the industry standard RCA clean for silicon photovoltaic applications. We present a unique method of processing the silicon surface effectively by UV-ozone cleaning. Despite being simple, UV-ozone cleaning results in a superior surface passivation quality that is comparable to high-quality RCA clean. When used as a stack dielectric--UV-ozone oxide overlaid by aluminum oxide--the thickness of UV-ozone oxide plays an important role in determining the passivation quality. Of all treatment times, 15 min of UV-ozone treatment results in an outstanding passivation quality, achieving the effective carrier lifetime of 3 ms and saturation current density of 5 fA/cm2. In addition, we present a simple and effective technique to extract values of electron/hole capture cross-section for the purpose of analyzing the interface passivation quality from already measured surface recombination parameters of saturation current density, interfacial trap density and total fixed charge, instead of measuring on the separately prepared metal-insulated-semiconductor (MIS) samples by the techniques: frequency-dependent parallel conductance or deep-level transient spectroscopy.
Download or read book Advances in Energy Research Vol 1 written by Suneet Singh and published by Springer Nature. This book was released on 2020-05-07 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected papers from the 6th International Conference on Advances in Energy Research (ICAER 2017), which cover topics ranging from energy optimization, generation, storage and distribution, and emerging technologies, to energy management, policy, and economics. The book is inter-disciplinary in scope and addresses a host of different areas relevant to energy research, making it of interest to scientists, policymakers, students, economists, rural activists, and social scientists alike.
Download or read book Electrical Properties of Silicon Surfaces and Interfaces written by Tracey Alexandra Burr and published by . This book was released on 1998 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amorphous and Polycrystalline Thin film Silicon Science and Technology 2006 written by Sigurd Wagner and published by . This book was released on 2007 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Nanoscopy written by Gustaaf van Tendeloo and published by John Wiley & Sons. This book was released on 2012-12-21 with total page 1484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This completely revised successor to the Handbook of Microscopy supplies in-depth coverage of all imaging technologies from the optical to the electron and scanning techniques. Adopting a twofold approach, the book firstly presents the various technologies as such, before going on to cover the materials class by class, analyzing how the different imaging methods can be successfully applied. It covers the latest developments in techniques, such as in-situ TEM, 3D imaging in TEM and SEM, as well as a broad range of material types, including metals, alloys, ceramics, polymers, semiconductors, minerals, quasicrystals, amorphous solids, among others. The volumes are divided between methods and applications, making this both a reliable reference and handbook for chemists, physicists, biologists, materials scientists and engineers, as well as graduate students and their lecturers.
