Download or read book Multi junction Thin Film Solar Cells for an Optimal Light Harvesting written by Paola Mantilla Pérez and published by . This book was released on 2017 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film photovoltaics encompass a group of technologies able to harvest light within a few microns thickness. The reduced thickness allows a low cost of manufacture while making the films flexible and adaptable to different surfaces. This, combined with their low weight, positioned thin film solar cells as ideal candidates for building integrated photovoltaics. For the latter, organic solar cells (OSC) can provide a high quality semi-transparency that closely mimics the aesthetics of standard windows. Indeed, some unique features of organic solar cells make them the optimal solution for applications where standard Si technology cannot be used. However, for large-scale electricity production where efficiency is, perhaps, the most determining factor, newer thin film technologies like perovskites solar cells may be a more adequate option. At the moment of writing this thesis, state of the art efficiencies of single junction perovskites nearly double that of the best single junction organic solar cell. A limitation found in both technologies, especially in organics and to a lesser degree in perovskites, is the low mobility of the carriers. This, together with other processing shortcomings in the organic absorbers and perovskites limit their thickness to 100-130 nm, and 500-600 nm, respectively. In summary, light management must be an essential ingredient when designing device architectures to achieve the optimal performance in the specific application being considered. In this thesis, in order to achieve an optimal light harvesting and therefore increase the performance of thin film solar cells, we take two approaches. On one hand, we increase the total thickness of the absorber material used in the device without increasing the thickness of the single active material layer and, on the other hand, we combine complementary absorbers to cover a wider portion of the solar spectra. These approaches pose the double challenge of finding the optimal electromagnetic field distribution within a complicated multilayer structure containing two or more active layers, while at the same time implementing an effective charge collection or recombination in the intermediate layers connecting two adjacent sub-cells. In the case of OSC, we consider multi-junction cells where the same active material is used in all the junctions. This can be implemented by fabricating structures where the active layer thickness in each sub-cell does not exceed the 100 nm. For other types of thin film solar cells, we consider configurations using complementary absorbers. In both cases, but particularly in the former one, a systematic approach to optimize light absorption is needed. In order to obtain such optimal configurations, we implement an inverse integration approach combined with a transfer matrix calculation of the electric field. Furthermore, we develop several new approaches to optimize charge collection in the sub-cell interconnection layers which we apply to tandem, triple, 4-terminal and series-parallel configurations. The thesis has been organized into five chapters. Chapter 1 introduces concepts required for the development of the thesis work including the optical model. Chapter 2 describes the optical optimization and experimental implementation of current-matched multi-junction devices using PTB7:PC71BM, including applications. In order to profit from the advantage of electrically separated devices, Chapter 3 evaluates different types of 4-terminal architectures using PTB7:PC71BM and PTB7-Th:PC71BM. In one of the architectures we establish a serial-connection between sub-cells while in other we leave the sub-cells completely independent. Chapter 4 theoretically proposes a novel monolithic architecture combining perovskites and CIGS which does not require current-matching. Finally, in Chapter 5, an in-depth study of the semi-transparent inner electrodes is given that include vacuum-based and solution-processed layers.
Download or read book Fabrication and Design of Sub wavelength Periodic Textures for Improving Light Harvesting in Multi junction III V Photovoltaics written by Wei Wang and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimization of non-planar antireflective coating and back- (or front-) surface texturing are widely studied to further reduce the reflection losses and increase the sunlight absorption path in solar cells. In III-V concentrator applications sunlight is focused onto the surface of cell and consequently, light arrives with a wide angular distribution that limits the effectiveness of conventional thin-film antireflective coatings (ARCs). Furthermore, the transmission properties are generally degraded non-uniformly over the electromagnetic spectrum, which in the case of multi-junction solar cells, leads to additional sub-cell current matching-related losses. Here, and in an attempt to identify a better alternative to the conventional dual-layer ARCs, a systematic analysis is undertaken regarding the design of parameters and angular dependent antireflective properties of dielectric grating formed through the implementation of sub-wavelength arrays of 2D pyramidal and hemispherical textures. The study includes evaluation of these properties for several common dielectrics through a careful selection of dielectric material and design. These structures can significantly surpass the performance of planar dual-layer ARCs, and the total number of reflected photons over 380-2000 nm wavelength range can be reduced to less than 2%, by use of single-material textured dielectric. It is also shown that the implementation of these structures for a typical concentrated 3 or 4 junction solar cells with apertures ranging from 0-60 degrees reduces total losses of reflected photons for each sub-cell to less than 4%, and therefore reduces current degradation. Back reflectors have been developed from perfect mirror to textured mirror in order to further increase light path, which can significantly improve the efficiency and allow for much-thinner devices. A Lambertian surface, which has the most random texture, can theoretically raise the light path to 4n2 times that of a smooth surface. It’s a challenge however to fabricate ideal Lambertian texture, especially in a fast and low cost way. In this work, a method is developed to overcome this challenge that combines the use of laser interference lithography and selective wet etching. The approach allows for a rapid wafer scale texture processing with subwavelength (nano-) scale control of the pattern and the pitch. The technique appears as being particularly attractive for the development of ultra-thin III-V devices, or in overcoming the weak sub-bandgap absorption in devices incorporating quantum dots or quantum wells (QWs). The design and fabrication process on the application of the technique for the development of back reflectors for MQWs solar cells are presented. Depending on the growth order (inverted or up-right growth), the two-side device-metallization incorporated with lift-off process are designed differently due to the fragile ultra-thin (~ 2 μm) active layer, and the strain from embedded QWs. Another approach is done through thinning the substrate (~ 15-20 μm), texturing the substrate as an incoherent reflector, and metallization, which won’t affect active layers.
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 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 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 The Future of Semiconductor Oxides in Next Generation Solar Cells written by Monica Lira-Cantu and published by Elsevier. This book was released on 2017-09-19 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Future of Semiconductor Oxides in Next-Generation Solar Cells begins with several chapters covering the synthesis of semiconductor oxides for NGSCs. Part II goes on to cover the types and applications of NGSCs currently under development, while Part III brings the two together, covering specific processing techniques for NGSC construction. Finally, Part IV discusses the stability of SO solar cells compared to organic solar cells, and the possibilities offered by hybrid technologies. This comprehensive book is an essential reference for all those academics and professionals who require thorough knowledge of recent and future developments in the role of semiconductor oxides in next generation solar cells. - Unlocks the potential of advanced semiconductor oxides to transform Next Generation Solar Cell (NGSC) design - Full coverage of new developments and recent research make this essential reading for researchers and engineers alike - Explains the synthesis and processing of semiconductor oxides with a view to their use in NGSCs
Download or read book Multi Junction Thin Film Solar Cells on Flexible Substrates for Space Power written by and published by . This book was released on 2002 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Novel Ultrathin LiF Interlayers for Efficient Light Harvesting in Thin film Si Tandem 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:
Download or read book Excitonic and Photonic Processes in Materials written by Jai Singh and published by Springer. This book was released on 2014-07-29 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is expected to present state-of-the-art understanding of a selection of excitonic and photonic processes in useful materials from semiconductors to insulators to metal/insulator nanocomposites, both inorganic and organic. Among the featured applications are components of solar cells, detectors, light-emitting devices, scintillators and materials with novel optical properties. Excitonic properties are particularly important in organic photovoltaics and light emitting devices, as also in questions of the ultimate resolution and efficiency of new-generation scintillators for medical diagnostics, border security and nuclear non proliferation. Novel photonic and optoelectronic applications benefit from new material combinations and structures to be discussed.
Download or read book Theory of Graded Bandgap Thin Film Solar Cells written by Faiz Ahmad and published by Springer Nature. This book was released on 2022-05-31 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin-film solar cells are cheap and easy to manufacture but require improvements as their efficiencies are low compared to that of the commercially dominant crystalline-silicon solar cells. An optoelectronic model is formulated and implemented along with the differential evolution algorithm to assess the efficacy of grading the bandgap of the CIGS, CZTSSe, and AlGaAs photon-absorbing layer for optimizing the power-conversion efficiency of thin-film CIGS, CZTSSe, and AlGaAs solar cells, respectively, in the two-terminal single-junction format. Each thin-film solar cell is modeled as a photonic device as well as an electronic device. Solar cells with two (or more) photon-absorbing layers can also be handled using the optolelectronic model, whose results will stimulate experimental techniques for bandgap grading to enable ubiquitous small-scale harnessing of solar energy.
Download or read book Advances in Thin Film Solar Cells written by I M Dharmadasa and published by CRC Press. This book was released on 2012-09-17 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book concentrates on the latest developments in our understanding of solid-state device physics. The material presented is mainly experimental and based on CdTe thin-film solar cells. It extends these new findings to CIGS thin-film solar cells and presents a new device design based on graded bandgap multilayer solar cells. This design has been experimentally tested using the well-researched GaAs/AlGaAs system and initial devices have shown impressive device parameters. These devices are capable of absorbing all radiation (UV, visible, and infra-red) within the solar spectrum and combines "impact ionization" and "impurity photovoltaic" effects. The improved device understanding presented in this book should impact and guide future device design and low-cost thin-film solar panel manufacture.
Download or read book Multi Junction Thin Film Solar Cells on Flexible Substrates for Space Power written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate objective of the thin-film program at NASA GRC is development of a 20 percent AM0 thin-film device technology with high power/weight ratio. Several approaches are outlined to improve overall device efficiency and power/weight ratio. One approach involves the use of very lightweight flexible substrates such as polyimides (i.e., Kapton(Trademark)) or metal foil. Also, a compound semiconductor tandem device structure that can meet this objective is proposed and simulated using Analysis of Microelectronic and Photonic Structures (AMPS). AMPS modeling of current devices in tandem format indicate that AM0 efficiencies near 20 percent can be achieved. And with improvements in materials, efficiencies approaching 25 percent are achievable. Several important technical issues need to be resolved to realize these complex devices: development of a wide bandgap material with good electronic properties, development of transparent contacts, and targeting a 2-terminal device structure (with more complicated processing and tunnel junction) or 4-terminal device. Recent progress in the NASA GRC program is outlined. Hepp, Aloysius F. and Smith, Mark and Scofield, John H. and Dickman, John E. and Lush, Gregory B. and Morel, Donald L. and Ferekides, Christos and Dhere, Neelkanth G. Glenn Research Center NASA/TM-2002-211834, NAS 1.15:211834, E-13528, IECEC-2002-20155
Download or read book Nanotechnology for Microelectronics and Photonics written by Raúl José Martín-Palma and published by Elsevier. This book was released on 2017-06-01 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology for Microelectronics and Photonics, Second Edition has been thoroughly revised, expanded, and updated. The aim of the book is to present the most recent advances in the field of nanomaterials, as well as the devices being developed for novel nanoelectronics and nanophotonic systems. It covers the many novel nanoscale applications in microelectronics and photonics that have been developed in recent years. Looking to the future, the book suggests what other applications are currently in development and may become feasible within the next few decades based on novel materials such as graphene, nanotubes, and organic semiconductors. In addition, the inclusion of new chapters and new sections to keep up with the latest developments in this rapidly-evolving field makes Nanotechnology for Microelectronics and Photonics, Second Edition an invaluable reference to research and industrial scientists looking for a guide on how nanostructured materials and nanoscale devices are used in microelectronics, optoelectronics, and photonics today and in future developments. - Presents the fundamental scientific principles that explain the novel properties and applications of nanostructured materials in the quantum frontier - Offers clear and concise coverage of how nanotechnology is currently used in the areas of microelectronics, optoelectronics, and photonics, as well as future proposed devices - Includes nearly a hundred problems along with helpful hints and full solutions for more than half of them
Download or read book Thin Film Solar Cells From Earth Abundant Materials written by Subba Ramaiah Kodigala and published by Newnes. This book was released on 2013-11-14 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental concept of the book is to explain how to make thin film solar cells from the abundant solar energy materials by low cost. The proper and optimized growth conditions are very essential while sandwiching thin films to make solar cell otherwise secondary phases play a role to undermine the working function of solar cells. The book illustrates growth and characterization of Cu2ZnSn(S1-xSex)4 thin film absorbers and their solar cells. The fabrication process of absorber layers by either vacuum or non-vacuum process is readily elaborated in the book, which helps for further development of cells. The characterization analyses such as XPS, XRD, SEM, AFM etc., lead to tailor the physical properties of the absorber layers to fit well for the solar cells. The role of secondary phases such as ZnS, Cu2-xS,SnS etc., which are determined by XPS, XRD or Raman, in the absorber layers is promptly discussed. The optical spectroscopy analysis, which finds band gap, optical constants of the films, is mentioned in the book. The electrical properties of the absorbers deal the influence of substrates, growth temperature, impurities, secondary phases etc. The low temperature I-V and C-V measurements of Cu2ZnSn(S1-xSex)4 thin film solar cells are clearly described. The solar cell parameters such as efficiency, fill factor, series resistance, parallel resistance provide handful information to understand the mechanism of physics of thin film solar cells in the book. The band structure, which supports to adjust interface states at the p-n junction of the solar cells is given. On the other hand the role of window layers with the solar cells is discussed. The simulation of theoretical efficiency of Cu2ZnSn(S1-xSex)4 thin film solar cells explains how much efficiency can be experimentally extracted from the cells. - One of the first books exploring how to conduct research on thin film solar cells, including reducing costs - Detailed instructions on conducting research
Download or read book McEvoy s Handbook of Photovoltaics written by Soteris Kalogirou and published by Academic Press. This book was released on 2017-08-24 with total page 1341 pages. Available in PDF, EPUB and Kindle. Book excerpt: Practical Handbook of Photovoltaics, Third Edition, is a 'benchmark' publication for those involved in the design, manufacture and use of these devices. This fully revised handbook includes brand new sections on smart grids, net metering and the modeling of photovoltaic systems, as well as fully revised content on developments in photovoltaic applications, the economics of PV manufacturing and updated chapters on solar cell function, raw materials, photovoltaic standards, calibration and testing, all with new examples and case studies. The editor has assembled internationally-respected contributors from industry and academia around the world to make this a truly global reference. It is essential reading for electrical engineers, designers of systems, installers, architects, policymakers and physicists working with photovoltaics. - Presents a cast of international experts from industry and academia to ensure the highest quality information from multiple stakeholder perspectives - Covers all things photovoltaics, from the principles of solar cell function and their raw materials, to the installation and design of full photovoltaic systems - Includes case studies, practical examples, and reports on the latest advances and worldwide applications
Download or read book Advances in III V Semiconductor Nanowires and Nanodevices written by Jianye Li and published by Bentham Science Publishers. This book was released on 2011-09-09 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Semiconductor nanowires exhibit novel electronic and optical properties due to their unique one-dimensional structure and quantum confinement effects. In particular, III-V semiconductor nanowires have been of great scientific and technological interest fo"
Download or read book Solar Cells and Modules written by Arvind Shah and published by Springer Nature. This book was released on 2020-07-16 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives a comprehensive introduction to the field of photovoltaic (PV) solar cells and modules. In thirteen chapters, it addresses a wide range of topics including the spectrum of light received by PV devices, the basic functioning of a solar cell, and the physical factors limiting the efficiency of solar cells. It places particular emphasis on crystalline silicon solar cells and modules, which constitute today more than 90 % of all modules sold worldwide. Describing in great detail both the manufacturing process and resulting module performance, the book also touches on the newest developments in this sector, such as Tunnel Oxide Passivated Contact (TOPCON) and heterojunction modules, while dedicating a major chapter to general questions of module design and fabrication. Overall, it presents the essential theoretical and practical concepts of PV solar cells and modules in an easy-to-understand manner and discusses current challenges facing the global research and development community.
