Download or read book Optimization of Top Contact for Cu In Ga Se2 Solar Cells written by Grace Cherukara Rajan and published by . This book was released on 2018 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimisation of Cu In Ga Se 1tn2 Thin Film Solar Cells and Modules for Low Irradiance Conditions written by Alessandro Virtuani and published by . This book was released on 2004 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Process Development and Optimisation for Efficient and Cost effective Cu In Ga Se2 Thin Film Solar Cells written by Zhengfei Wei and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Selective TiO2 Contact for Cu In Ga Se2 Solar Cells written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The non-toxic and wide bandgap material TiO2 is explored as an n-type buffer layer on p-type Cu(In, Ga)Se2 (CIGS) absorber layer for thin film solar cells. The amorphous TiO2 thin film deposited by atomic layer deposition process at low temperatures shows conformal coverage on the CIGS absorber layer. Solar cells from non-vacuum deposited CIGS absorbers with TiO2 buffer layer result in a high short-circuit current density of 38.9 mA/cm2 as compared to 36.9 mA/cm2 measured in the reference cell with CdS buffer layer, without compromising open-circuit voltage. The significant photocurrent gain, mainly in the UV part of the spectrum, can be attributed to the low parasitic absorption loss in the ultrathin TiO2 layer (~10 nm) with a larger bandgap of 3.4 eV compared to 2.4 eV of the traditionally used CdS. Overall the solar cell conversion efficiency was improved from 9.5% to 9.9% by substituting the CdS by TiO2 on an active cell area of 10.5 mm2. In conclusion, optimized TiO2/CIGS solar cells show excellent long-term stability. The results imply that TiO2 is a promising buffer layer material for CIGS solar cells, avoiding the toxic CdS buffer layer with added performance advantage.

Download or read book Optical Physics of Cu In Ga Se2 Solar Cells and Their Layer Components written by Abedl-Rahman Ibdah and published by . This book was released on 2016 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycrystalline Cu(In1-xGax)Se2 (CIGS) thin film technology has emerged as a promising candidate for low cost and high performance solar modules. The efficiency of CIGS solar cells is strongly influenced by several key factors. Among these factors include Ga composition and its profile in the absorber layer, copper content in this layer, and the solar cell multilayer structure. As a result, tools for the characterization of thin film CIGS solar cells and their layer components are becoming increasingly essential in research and manufacturing. Spectroscopic ellipsometry is a non-invasive technique that can serve as an accurate probe of component layer optical properties and multilayer structures, and can be applied as a diagnostic tool for real-time, in-line, and off-line monitoring and analysis in small area solar cell fabrication as well as in large area photovoltaics manufacturing. Implementation of spectroscopic ellipsometry provides unique insights into the properties of complete solar cell multilayer structures and their layer components. These insights can improve our understanding of solar cell structures, overcome challenges associated with solar cell fabrication, and assist in process monitoring and control on a production line. In this dissertation research, Cu(In,Ga)Se2 films with different Cu contents have been prepared by the one stage co-evaporation process. These films have been studied by real time spectroscopic ellipsometry (RTSE) during deposition, and by in-situ SE at the deposition temperature as well as at room temperature to extract the dielectric functions (e1, e2) of the thin film materials. Analytical expressions for the room temperature dielectric functions were developed, and the free parameters that describe these analytical functions were in turn expressed as functions of the Cu content. As a result of this parameterization, the dielectric function spectra (e1, e2) can be predicted for any desired composition within the range of the samples investigated. This capability was applied for mapping the structural and compositional variations of CIGS thin films deposited over a 10 cm × 10 cm substrate area. In another application presented in this dissertation, a non-invasive method utilizing ex-situ spectroscopic ellipsometry analysis has been developed and applied to determine non-destructively the Ga compositional profile in CIGS absorbers. The method employs parameterized dielectric function spectra (e1, e2) of CIGS versus Ga content to probe the compositional variation with depth into the absorber. In addition, a methodology for prediction of the external quantum efficiency (QE) including optical gains and losses for a CIGS solar cell has been developed. The methodology utilizes ex-situ spectroscopic ellipsometry analysis of a complete solar cell, with no free parameters, to deduce the multilayer solar cell structure non-invasively and simulate optical light absorption in each of the layer components. In the case of high efficiency CIGS solar cells, with minimal electronic losses, QE spectra are predicted from the sum of optical absorption in the active layer components. For such solar cells with ideal photo-generated charge carrier collection, the SE-predicted QE spectra are excellent representation of the measured ones. Since the QE spectra as well as the short circuit current density (Jsc) can be calculated directly from SE analysis results, then the predicted QE from SE can be compared with the experimental QE to evaluate electronic losses based on the difference between the spectra. Moreover, the calculated Jsc can be used as a key parameter for the design and optimization of anti-reflection coating structures. Because the long term production potential of CIGS solar modules may be limited by the availability of indium, it becomes important to reduce the thickness of the CIGS absorber layer. Thickness reduction would reduce the quantity of indium required for production which would in turn reduce costs. A decrease in short-circuit current density (Jsc) is expected, however, upon thinning the CIGS absorber due to incomplete absorption. To clarify the limits of obtainable Jsc in ultra-thin CIGS solar cells with Mo back contacts, optical properties and multilayer structural data are deduced via spectroscopic ellipsometry analysis and used to predict the QE spectra and maximum obtainable Jsc values upon thinning the absorber. Moreover, SE-guided optical design of ultra-thin CIGS solar cells has been demonstrated. In the case of solar cells fabricated on Mo, thinning the absorber in a CIGS solar cell is associated with significant optical losses in the Mo containing back contact layers. This is due in part to the poor optical reflectance of Mo. Such optical losses may be reduced by employing a back contact design with improved reflectance. Thus, alternative novel solar cell structures with ultra-thin absorbers and improved back contact reflectance have been designed and investigated using SE and the optical modeling methods. In addition to optical losses, electronic losses in the ultra-thin solar cells have been evaluated. By separating the absorber layer into sub-layer regions (for example, near-junction, bulk, and near-back-contact) and varying carrier collection probability in these regions, the contribution of each region to the current can be estimated. Based on this separation, the origin of the electronic losses has been identified as near the back contact.

Download or read book Growing Cu In Ga Se2 Thin Film Solar Cells with High Efficiency and Low Production Costs written by Shihang Yang and published by . This book was released on 2012 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two major approaches are performed to improve solar cell performances. Light trapping by etching AZO top contact for creating pyramid-structures to enhance light scattering. Efficiency is increased by more than 1.5% for solar cells with etched AZO surfaces. Solar cells with efficiency larger than 13% can be grown by using AZO etching. Another approach is by using suitable Ga content in absorber layer. Solar cells with efficiency as high as 14.17% are grown which makes thinner CIGS solar cells very competitive.

Download or read book Optimization of Cu In Ga S Se 2 Thin Film Solar Cell Using Sequential Sputtering selenization and Sulfurization written by 黃鵬丞 and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integration of Highly Reflective Back Contacts in Microstructured Cu In Ga Se2 Solar Cells written by Thomas Schneider and published by . This book was released on 2023* with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis deals with the introduction of a highly-reflective back contact in Cu(In,Ga)Se2 (CIGSe) based solar cells. Such a back contact can be used to compensate for the optical losses, which correspond with such a reduction. Such a reduction would enable a cost reduction of this solar cell type. It was demonstrated that an Al/ITO-based back contact has compared to the regularly used Mo-back contact a considerably increased reflection. Interestingly, the investigated back contact is also compatible with process temperatures as high as 600°C. The described back contact was also combined with a nanostructured substrate. Finally, the measured data was furthermore used to obtain general insights into the admittance spectroscopy of CIGSe solar cells.

Download or read book Anticipated Performance of Cu In Ga Se2 Solar Cells in the Thin film Limit written by Ana Kanevce and published by . This book was released on 2007 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization of Process Parameters for Faster Deposition of CuIn1x Gax S2 and CuIn1x Gax Se2 y Sy Thin Film Solar Cells written by Ashwani Kaul and published by . This book was released on 2012 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film solar cells have the potential to be an important contributor to the world energy demand in the 21st century. Among all the thin film technologies, CuInGaSe2 (CIGS) thin film solar cells have achieved the highest efficiency. However, the high price of photovoltaic (PV) modules has been a major factor impeding their growth for terrestrial applications. Reduction in cost of PV modules can be realized by several ways including choosing scalable processes amenable to large area deposition, reduction in the materials consumption of active layers, and attaining faster deposition rates suitable for in-line processing. Selenization-sulfurization of sputtered metallic Cu-In-Ga precursors is known to be more amenable to large area deposition. Sputter-deposited molybdenum thin film is commonly employed as a back contact layer for CIGS solar cells. However, there are several difficulties in fabricating an optimum back contact layer. It is known that molybdenum thin films deposited at higher sputtering power and lower gas pressure exhibit better electrical conductivity. However, such films exhibit poor adhesion to the soda-lime glass substrate. On the other hand, films deposited at lower discharge power and higher pressure although exhibit excellent adhesion show lower electrical conductivity. Therefore, a multilayer structure is normally used so as to get best from the two deposition regimes. A multi-pass processing is not desirable in high volume production because it prolongs total production time and correspondingly increases the manufacturing cost. In order to make manufacturing compliant with an in-line deposition, it is justifiable having fewer deposition sequences. Thorough analysis of pressure and power relationship of film properties deposited at various parameters has been carried out. It has been shown that it is possible to achieve a molybdenum back contact of desired properties in a single deposition pass by choosing the optimum deposition parameters. It is also shown that the film deposited in a single pass is actually a composite structure. CIGS solar cells have successfully been completed on the developed single layer back contact with National Renewable Energy Laboratory (NREL) certified device efficiencies [greater than]11%. The optimization of parameters has been carried out in such a way that the deposition of back contact and metallic precursors can be carried out in identical pressure conditions which is essential for in-line deposition without a need for load-lock. It is know that the presence of sodium plays a very critical role during the growth of CIGS absorber layer and is beneficial for the optimum device performance. The effect of sodium location during the growth of the absorber layer has been studied so as to optimize its quantity and location in order to get devices with improved performance. NREL certified devices with efficiencies [greater than]12% have been successfully completed.

Download or read book Advanced Back Contacts for Flexible Cu In Ga Se2 Solar Cells written by Patrick Blösch 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 Chalcogenide Photovoltaics written by Roland Scheer and published by John Wiley & Sons. This book was released on 2011-03-31 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive description of the most important material properties and device aspects closes the gap between general books on solar cells and journal articles on chalcogenide-based photovoltaics. Written by two very renowned authors with years of practical experience in the field, the book covers II-VI and I-III-VI2 materials as well as energy conversion at heterojunctions. It also discusses the latest semiconductor heterojunction models and presents modern analysis concepts. Thin film technology is explained with an emphasis on current and future techniques for mass production, and the book closes with a compendium of failure analysis in photovoltaic thin film modules. With its overview of the semiconductor physics and technology needed, this practical book is ideal for students, researchers, and manufacturers, as well as for the growing number of engineers and researchers working in companies and institutes on chalcogenide photovoltaics.

Download or read book Alternative Buffer Layer Development in Cu In Ga Se2 Thin Film Solar Cells written by Peipei Xin and published by . This book was released on 2017 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cu(In,Ga)Se2-based thin film solar cells are considered to be one of the most promising photovoltaic technologies. Cu(In,Ga)Se2 (CIGS) solar devices have the potential advantage of low-cost, fast fabrication by using semiconductor layers of only a few micrometers thick and high efficiency photovoltaics have been reported at both the cell and the module levels. CdS via chemical bath deposition (CBD) has been the most widely used buffer option to form the critical junction in CIGS-based thin film photovoltaic devices. However, the disadvantages of CdS can’t be ignored - regulations on cadmium usage are getting stricter primarily due to its toxicity and environmental impacts, and the proper handling of the large amount of toxic chemical bath waste is a massive and expensive task. ☐ This dissertation is devoted to the development of Cd-free alternative buffer layers in CIGS-based thin film solar cells. Based on the considerations of buffer layer selection criteria and extensive literature review, Zn-compound buffer materials are chosen as the primary investigation candidates. Radio frequency magnetron sputtering is the preferred buffer deposition approach since it’s a clean and more controllable technique compared to CBD, and is readily scaled to large area manufacturing. ☐ First, a comprehensive study of the ZnSe1-xOx compound prepared by reactive sputtering was completed. As the oxygen content in the reactive sputtering gas increased, ZnSe1-xOx crystallinity and bandgap decreased. It’s observed that oxygen miscibility in ZnSe was low and a secondary phase formed when the O2 / (O2 + Ar) ratio in the sputtering gas exceeded 2%. Two approaches were proposed to optimize the band alignment between the CIGS and buffer layer. One method focused on the bandgap engineering of the absorber, the other focused on the band structure modification of the buffer. As a result, improved current of the solar cell was achieved although a carrier transport barrier at the junction interface still limited the device performance. ☐ Second, an investigation of Zn(S,O) buffer layers was completed. Zn(S,O) films were sputtered in Ar using a ZnO0.7S0.3 compound target. Zn(S,O) films had the composition close to the target with S / (S+O) ratio around 0.3. Zn(S,O) films showed the wurtzite structure with the bandgap about 3.2eV. The champion Cu(In,Ga)Se2 / Zn(S,O) cell had 12.5% efficiency and an (Ag,Cu)(In,Ga)Se2 / Zn(S,O) cell achieved 13.2% efficiency. Detailed device analysis was used to study the Cu(In,Ga)Se2 and (Ag,Cu)(In,Ga)Se2 absorbers, the influence of absorber surface treatments, the effects of device treatments, the sputtering damage and the Na concentration in the absorber. ☐ Finally alternative buffer layer development was applied to an innovative superstrate CIGS configuration. The superstrate structure has potential benefits of improved window layer properties, cost reduction, and the possibility to implement back reflector engineering techniques. The application of three buffer layer options – CdS, ZnO and ZnSe was studied and limitations of each were characterized. The best device achieved 8.6% efficiency with a ZnO buffer. GaxOy formation at the junction interface was the main limiting factor of this device performance. For CdS / CIGS and ZnSe / CIGS superstrate devices extensive inter-diffusion between the absorber and buffer layer under CIGS growth conditions was the critical problem. Inter-diffusion severely deteriorated the junction quality and led to poorly behaved devices, despite different efforts to optimize the fabrication process.

Download or read book Effective Processing Conditions for Cu In Ga Se2 Solar Cells Using an Additional Copper Layer written by Harish Sankaranarayanan and published by . This book was released on 1998 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanocoatings Nanosystems Nanotechnologies written by Alexander D. Pogrebnjak and published by Bentham Science Publishers. This book was released on 2012-09-17 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Reference eBook deals with an existing classification of a nanosized structure and an analysis of its properties. It summarizes an information about how a grain size affects physical, mechanical, thermal, and other properties of a nanostructured material. A basic method, which is employed for a fabrication of an isolated nanoparticle, an ultradisperse powder, a compact nanocystalline, nanoporous, and amorphous material, a fullerene, a nanotube, and a nanostuctured coating, is considered. Investigation methods, which are applied to study the nanostructured material, are briefly described. A modern understanding of a formation of the nanostructured and nanocomposite coating, which are fabricated using a ion-plasma deposition method, is reposted. A potential application of the nanostructured material and coating in a field of engineering is demonstrated. Readership: Graduate, Postgraduate, Ph.D. Students, Researchers and Industry Professionals. The eBook contains 9 Chapters, 87 Figures, 14 Tables, 411 References-totally, 155 Pages. It was approved by two Scientific Boards from National Kharkov University and Sumy State University. A main content of this eBook is a basis for lectures presented for students at Sumy State University (the Physical-Technical Faculty), Kharkov National University (the Physical Faculty), Omsk State University (the Physical Faculty, the Department of Material Science), East-Kazakhstan State Technical University (Ust-Kamenogorsk, Kazakhstan), and Moscow State University (the Physical Faculty, Moscow, Russia). A source of this eBook is original papers of leading world-known scientists, who ware involved in a field of new nano composite material fabrication, nanotechnologies, and researches. This version had not been published elsewhere. It is interesting for a wide circle of specialists, Masters, aspirants, scientific researchers, and a technical staff of Higher Education System, Research Institutes and Laboratories. It covers recent data since 2008 to 2010 year.

Download or read book Process development for highly efficient flexible Cu In Ga Se2 solar cells written by Adrian Chirilă and published by . This book was released on 2012 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization of Front Contact Grid Patterns for Solar Cells written by Priyavadan Ramdas Patel and published by . This book was released on 1981 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: