Download or read book Crystalline Silicon Surface Passivation Using Aluminum Oxide Fundamental Understanding and Application to Solar Cells written by Boris Adrian Veith-Wolf and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aluminum Oxide for the Surface Passivation of High Efficiency Silicon Solar Cells written by Armin Richter and published by . This book was released on 2015-02-23 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic Layer Deposition of Aluminum Oxide on Crystalline Silicon written by Florian Werner and published by . This book was released on 2014 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Perspectives on Surface Passivation Understanding the Si Al2O3 Interface written by Lachlan E. Black and published by Springer. This book was released on 2016-04-15 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book addresses the problem of passivation at the surface of crystalline silicon solar cells. More specifically, it reports on a high-throughput, industrially compatible deposition method for Al2O3, enabling its application to commercial solar cells. One of the main focus is on the analysis of the physics of Al2O3 as a passivating dielectric for silicon surfaces. This is accomplished through a comprehensive study, which moves from the particular, the case of aluminium oxide on silicon, to the general, the physics of surface recombination, and is able to connect theory with practice, highlighting relevant commercial applications.
Download or read book Surface Passivation of Industrial Crystalline Silicon Solar Cells written by Joachim John and published by Institution of Engineering and Technology. This book was released on 2018-11-15 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface passivation of silicon solar cells describes a technology for preventing electrons and holes to recombine prematurely with one another on the wafer surface. It increases the cell's energy conversion efficiencies and thus reduces the cost per kWh generated by a PV system.
Download or read book Sputtered Aluminium Oxide and Amorphous Silicon for Silicon Solar Cells written by Xinyu Zhang and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-efficiency silicon solar cells have been attracting an increased interest in recent years. Surface passivation is essential for various types of high-performance solar cells, particularly when thinner silicon wafers are used to reduce the material cost. Passivating dielectric thin films have been widely studied and used in solar cells designs, these include atomic-layer deposited (ALD) aluminium oxide, plasma-enhanced chemical vapour deposited (PECVD) silicon nitride and PECVD intrinsic amorphous silicon. The aim of this thesis is to develop and optimise an alternative deposition method for surface passivating films: sputtering. Sputtering is especially attractive for industrial production, due to its high throughput, easy and safe operation and global cost-effectiveness. This thesis has focussed on optimising the reactive sputtering of aluminium oxide, using an aluminium target, and the non-reactive sputtering of amorphous silicon, using a silicon target. A key innovation has been the addition of hydrogen to the mix of gasses that form the plasma, which permits to incorporate hydrogen into the films, leading to a significantly improved surface passivation quality compared to non-hydrogenated films. We have achieved the best surface passivation results by sputtered aluminium oxide to date, with an effective surface recombination velocity of 1 cm/s on 1.5 ohm-cm n-type silicon. This result is similar to the SRV of 0.9 cm/s measured on aluminium oxide films deposited by PA-ALD on the same substrates. Good passivation was also achieved on p-type silicon. The investigations into the reactive sputtering process have shown that the film properties are closely related to the oxidation level of the aluminium target, which can be controlled by adjusting process parameters. It has also been found that the presence of hydrogen in the plasma is beneficial for establishing the optimum conditions of the deposition; not only does the surface passivation quality improve, but the reactive sputtering process becomes easier to control as well.We have also shown - for the first time - that intrinsic amorphous silicon (a-Si:H) films by sputtering deposition are capable of providing an excellent passivation of crystalline silicon surfaces. A SRV of 1.5 cm/s on 1.5 ohm-cm n-type silicon and SRV of 9 cm/s on 1 ohm-cm p-type silicon have been achieved, which are comparable to the commonly used PECVD deposited a-Si:H films. After investigating the film properties using Fourier Transform Infrared Spectroscopy (FTIR), we observe that our sputtered a-Si:H films have a characteristic signature in terms of chemical bonding configurations, where several types of silicon-hydrogen bonds exist. From those measurements we have estimated that there is approximately a 4% hydrogen concentration in the films, sufficient to achieve excellent surface passivation. Finally, the thesis also presents initial attempts at developing doped amorphous silicon films, which could enable the development of an all-sputtered silicon heterojunction solar cell technology. Lightly doped a-Si:H films were deposited using a 1% boron doped silicon target and a 0.01% phosphorus doped silicon target. We have found an appropriate way to avoid surface passivation degradation caused by the doped layer deposition onto an intrinsic a-Si:H layer.
Download or read book Development of High efficiency Solar Cells on Thin Silicon Through Design Optimization and Defect Passivation written by Manav Sheoran and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall goal of this research is to improve fundamental understanding of the hydrogen passivation of defects in low-cost silicon and the fabrication of high-efficiency solar cells on thin crystalline silicon through low-cost technology development. A novel method was developed to estimate the flux of hydrogen, released from amorphous silicon nitride film, into the silicon. Rapid-firing-induced higher flux of hydrogen was found to be important for higher defect passivation. This was followed by the fabrication of solar cell efficiencies of ~ 17% on low-cost, planar cast multicrystalline silicon. Solar cell efficiencies and lifetime enhancement in the top, middle, and bottom regions of cast multicrystalline silicon ingots were explained on the basis of impurities and defects generally found in those regions. In an attempt to further reduce the cost, high-efficiency solar cells were fabricated on thin crystalline silicon wafers with full area aluminum-back surface field. In spite of loss in efficiency, wafer thinning reduced the module cost. Device modeling was performed to establish a roadmap towards high-efficiency thin cells and back surface recombination velocity and back surface reflectance were identified as critical parameters for high-efficiency thin cells. Screen-printed solar cells on float zone material, with efficiencies> 19% on 300 Îơm and> 18% on 140 Îơm were fabricated using a novel low-cost fabrication sequence that involved dielectric rear passivation along with local contacts and back surface field.
Download or read book Crystalline Silicon Solar Cells written by Armin G. Aberle and published by . This book was released on 1999 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Understanding and Application of Screen printed Metallization Aluminum Back Surface Fields and Dielectric Surface Passivation for High efficiency Silicon Solar Cells written by Shreesh Narasimha and published by . This book was released on 1999 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Realistic Operation Conditions on Silicon Solar Cells and Energy Yield written by Rebekka Eberle and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis discusses studies performed by the author at the Fraunhofer Institute for Solar Energy Systems, ISE. The main goal of this thesis was the analysis temperature sensitivities of silicon solar cells based on experimental data and simulation studies. The main achievements are: •A literature review of studies of temperature-dependent solar cell characteristics is given. The review provides a basis of fundamental physics behind temperature sensitivity of solar cells and helps to understand the underlying physics of local temperature dependencies in mono- as well as multicrystalline silicon. •Measurement approaches for spatially-resolved temperature-dependent characterization of silicon wafers and solar cells were developed. For silicon wafers the method is based on lifetime-calibrated photoluminescence imaging, measurements are completed between 15°C to up to 70°C, which represent realistic temperatures of operation. Silicon solar cells are characterized by photoluminescence imaging, lock-in thermography as well as light-beam-induced-current measurements in a temperature dependent manner to assess local temperature sensitivity of cell performance. •The temperature dependence of three different regions of silicon solar cells have been investigated: (i) the bulk, (ii) surfaces and (iii) diffused regions. •(i) A broad study of the temperature-dependent local open-circuit voltage VOC based on bulk lifetime measurements was conducted. Very different materials ranging from standard industrial multicrystalline silicon to high quality float zone silicon were characterized for their temperature sensitivity of VOC by lifetime-calibrated photoluminescence imaging. It it shown that for some multicrystalline samples, a deviation to the analytical temperature sensitivity is obvious in areas with high dislocation density, the same does not occur in high quality sample areas. From this extensive study and its broad variety of data it is concluded that uncontaminated crystal defects such as sliplines or dislocation clusters do not influence a cell's temperature sensitivity outside literature expectation. However, possibly contamination with metals which induce a SRH defect level of Et-E¬v or Ec-E¬t of 0.2 eV to 0.3 eV with low symmetry factor may lead to decreased temperature sensitivity due to a strong increase in effective lifetime eff with increasing temperature. •(ii) The temperature-dependent surface recombination velocity was investigated via a thickness variation of float zone samples with surface passivation of aluminum-oxide. The experimental investigation showed that surface recombination is highly dependent on temperature and its temperature sensitivity might be influenced by excess charge carrier density n. •(iii) To get insights into the physics behind temperature sensitivity of silicon solar cells the temperature dependence of recombination in diffused layers, such as the emitter, is studied by an analysis of the dark saturation current J0. Via a variation of emitter dopant and sheet resistivity it is shown that J0/ni2, which was commonly assumed to be independent of temperature, is increasing significantly with temperature and neglecting its temperature sensitivity can cause errors of up to 30 % for studied samples in this thesis. This behaviour seems to be independent of injection and sheet resistivity. •A sensitivity analysis was conducted to demonstrate how new findings about temperature sensitivity of silicon solar cells influence numerical simulations of silicon solar cell devices. It is shown that the implementation of further temperature dependencies of input parameters into device simulation leads to deviations to temperature coefficients from common simulations of several percent. Wrong assumptions of temperature-dependent bulk lifetime, emitter recombination and contact resistivity affect the simulated efficiency at temperatures deviating from STC. However, this effect is too weak to affect predicted energy yield significantly. •The yearly energy yield for silicon solar modules is predicted via measurements at wafer level before metallization in spatial resolution. In most multicrystalline silicon solar cells highly contaminated dislocation clusters are characterized by decreased temperature sensitivity, which leads to higher energy yield when it is normalized to its power at STC. Hence, improved temperature sensitivity leads to a decreasing gap between bad and good areas in mutlicrystalline silicon at higher temperatures. However, this improved temperature sensitivity cannot compensate the overall reduced material quality and the overall yearly energy yield is still lower in areas of minor material quality compared to high quality areas. •The conducted studies give valuable insights into temperature sensitivities of silicon solar cells and their device layers as well as bulk material, and furthermore, how they influence the silicon solar modules' energy yield. The shown approaches shall enable an optimization of silicon solar cells for realistic operation temperatures. Analyzing the influence of various processing steps on a solar cell's temperature sensitivity as well as identifying local inhomogeneity are key parameters to improve temperature coefficients of silicon solar cells in order to increase the yearly energy yield of solar modules for the intended location of operation
Download or read book Facile Grown Native Oxide Based Passivation of Crystalline Silicon written by A. K. M. Zahidur Rahim Chowdhury and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crystalline Silicon Surface Passivation by Amorphous Silicon Compounds written by Roman Petres and published by Sudwestdeutscher Verlag Fur Hochschulschriften AG. This book was released on 2011-09 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells based on crystalline silicon (c-Si) have the potential to make photovoltaic electricity cheaper than coal-based electric power generation within less than 10 years. The largest cost decrease potential on the cell level lies with improved electronic surface passivation. In this work, the current industry standard, amorphous silicon nitride (a-SiNx: H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD), is investigated and compared to amorphous silicon carbide, silicon carbonitride and silicon oxynitride films deposited by both high- and for the first time also low-frequency (LF) PECVD. It is shown that and an explanation offered as to why LF PECVD is capable of excellent surface passivation, comparable to remote-plasma results in literature and higher than previously published for LF PECVD. The achieved surface passivation quality is sufficient for dielectric rear-surface passivation without an underlying diffused back surface field. It is also shown that the purity grade of precursor gases used for film deposition can be lowered significantly without affecting cell efficiency and long-term stability on the module level, allowing for further cost reduction
Download or read book Low temperature Surface Passivation of Crystalline Silicon and Its Application to the Rear Side of Solar Cells written by Stefan Dauwe and published by . This book was released on 2004 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Materials Concepts For Solar Cells Second Edition written by Thomas Dittrich and published by World Scientific Publishing Company. This book was released on 2018-01-30 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modern challenge is for solar cell materials to enable the highest solar energy conversion efficiencies, at costs as low as possible, and at an energy balance as sustainable as necessary in the future. This textbook explains the principles, concepts and materials used in solar cells. It combines basic knowledge about solar cells and the demanded criteria for the materials with a comprehensive introduction into each of the four classes of materials for solar cells, i.e. solar cells based on crystalline silicon, epitaxial layer systems of III-V semiconductors, thin-film absorbers on foreign substrates, and nano-composite absorbers. In this sense, it bridges a gap between basic literature on the physics of solar cells and books specialized on certain types of solar cells.The last five years had several breakthroughs in photovoltaics and in the research on solar cells and solar cell materials. We consider them in this second edition. For example, the high potential of crystalline silicon with charge-selective hetero-junctions and alkaline treatments of thin-film absorbers, based on chalcopyrite, enabled new records. Research activities were boosted by the class of hybrid organic-inorganic metal halide perovskites, a promising newcomer in the field.This is essential reading for students interested in solar cells and materials for solar cells. It encourages students to solve tasks at the end of each chapter. It has been well applied for postgraduate students with background in materials science, engineering, chemistry or physics.
Download or read book Study of Surface Passivation Behavior of Crystalline Silicon Solar Cells written by Haider Ali and published by . This book was released on 2017 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve efficiencies approaching the theoretical limit of 29.4% for industrially manufactured solar cells based on crystalline silicon, it is essential to have very low surface recombination velocities at both the front and rear surfaces of the silicon substrate. Typically, the substrate surfaces feature contacted and uncontacted regions, and recombination should be limited for both to maximize the energy conversion efficiency.
