Download or read book Light Trapping in Solar Cells Using Resonant Nanostructures written by and published by . This book was released on 2013 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Photovoltaics is a sustainable and environmentally clean source of energy that has the potential to become a major source of energy for our society. In order for this to happen, photovoltaics needs to be economically competitive with other conventional energy sources. This can be achieved by reducing the production costs of solar panels and by improving their photovoltaic conversion efficiency. For Si solar cells, both challenges can be achieved by reducing the thickness of the solar cell. However, major optical losses occur when the thickness of Si solar cell is reduced, due to incomplete absorption of light. In this thesis, we investigate new ways of enhancing light absorption in Si solar cells by using nanostructures that show resonant interaction with light. We study the fundamental aspects of resonant scattering of light by metallic and dielectric nanoparticles placed on top of thick and thin dielectric substrates. If optimally designed these nanostructures can lead to efficient light coupling and trapping in solar cells. This allows the realization of novel solar cell architectures with higher efficiency that can be made at lower costs."--Samenvatting auteur.

Download or read book Light Trapping in Thin film Solar Cells Using Dielectric and Metallic Nanostructures written by and published by . This book was released on 2014 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Photovoltaics (PV) is a sustainable and clean source of energy and the sun provides more than enough energy to make PV a major electricity source. To make PV fully competitive with conventional energy sources, a reduction of the cost per watt is required. This can be achieved by increasing the conversion efficiency of the modules or by decreasing manufacturing cost. Thin-film solar cells offer the potential for lower manufacturing costs. They can also serve as top cells in high-efficiency tandem solar cells. A major problem with thin-film solar cells is the incomplete absorption of the solar spectrum, which leads to a drastic reduction of the efficiency. To enhance the absorption of light in thin-film solar cells light trapping is required, in which nanostructures are integrated in the cell to enhance the path length of the light in the absorber layer. In this thesis we present new insights in light trapping in thin-film hydrogenated amorphous Si (a-Si:H) and Cu(In,Ga)Se2 (CIGSe) solar cells. We experimentally study arrays of metallic and dielectric resonant scatterers at the front and at the back side of thin-film solar cells, and demonstrate efficient light trapping without deterioration of the electrical properties of the devices. We emphasize the relevance of minimizing optical losses in the light trapping patterns. We compare periodic and random scattering patterns and demonstrate the importance of the spatial frequency distribution in the scattering patterns. We present an optimization of the spatial frequency distribution of light trapping patterns that is applicable to all thin-film solar cell types."-Samenvatting auteur.

Download or read book Introduction to Light Trapping in Solar Cell and Photo detector Devices written by Stephen J. Fonash and published by Elsevier. This book was released on 2014-09-15 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: New Approaches to Light Trapping in Solar Cell Devices discusses in detail the use of photonic and plasmonic effects for light trapping in solar cells. It compares and contrasts texturing, the current method of light-trapping design in solar cells, with emerging approaches employing photonic and plasmonic phenomena. These new light trapping methods reduce the amount of absorber required in a solar cell, promising significant cost reduction and efficiency. This book highlights potential advantages of photonics and plasmonics and describes design optimization using computer modeling of these approaches. Its discussion of ultimate efficiency possibilities in solar cells is grounded in a review of the Shockley-Queisser analysis; this includes an in-depth examination of recent analyses building on that seminal work.

Download or read book Nanotechnology for Energy Sustainability written by Baldev Raj and published by John Wiley & Sons. This book was released on 2017-01-27 with total page 1487 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses Referenzwerk in drei handlichen Bänden bietet einen detaillierten Überblick über Anwendungen der Nanotechnologie im Bereich Nachhaltigkeit in der Energieversorgung. Der erste Band dieses klar strukturierten Nachschlagewerks behandelt nach der Einleitung die Themen Energieerzeugung, erneuerbare Energien, Energiespeicherung, Energieverteilung sowie Energieumwandlung und Energy-Harvesting. Im zweiten Band werden auf Nanotechnologie basierte Materialen, Energieeinsparung und -management, technologische und urheberrechtlich relevante Fragen, Märkte und Umweltsanierung erörtert. Der dritte Band wirft einen Blick in die Zukunft, auf technologische Fortschritte und gibt Empfehlungen. Ein wichtiges Handbuch für alle Experten auf diesem Gebiet, von Forschern und Ingenieuren im wissenschaftlichen Bereich bis hin zu Entwicklern in der Industrie.

Download or read book Design and Fabrication of Nanostructures for Light trapping in Ultra thin Solar Cells written by Inès Massiot and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reducing the absorber thickness is an attractive solution to decrease the production cost of solar cells. Furthermore, it allows to reduce the amount of material needed and improve the current collection in the cell. This thesis has been focused on the design of nanostructures to enhance light absorption in very small semiconductor volumes in order to achieve efficient ultra-thin solar cells. First, we have proposed an original light-trapping concept for ultra-thin amorphous silicon (a-Si:H) solar cells. A one-dimensional metallic grating is patterned on the front surface of the cell deposited on a metallic mirror. Broadband multi-resonant absorption has been demonstrated for both light polarizations. The metallic grating is also used as an alternative transparent electrode in order to reduce optical losses in the front contact. A detailed analysis of the multi-resonant absorption mechanism has been carried out through numerical calculations. The fabrication and optical characterization of ultra-thin a-Si:H solar cells with metallic gratings have validated the multi-resonant approach.Second, we have proposed a design with a two-dimensional metallic grid as a resonant front contact for very thin (25 nm) gallium arsenide (GaAs) layers. We have shown through the design and fabrication of a proof-of-concept structure the potential of metallic nanogrids to confine efficiently light absorption with an ultra-thin GaAs layer.Finally, advanced light-trapping structures could also allow a thickness reduction of crystalline silicon wafers of a factor 20 to 100 with respect to state-of-the-art cells. We have developed a process to transfer micron-thick epitaxial crystalline silicon (c-Si) layers onto a low-cost host substrate. Inverted nanopyramids have also been fabricated in crystalline silicon in order to achieve a broadband anti-reflection effect. It opens promising perspectives towards the realization of double-sided nanopatterned ultra-thin c-Si cells.

Download or read book Anti reflection and Light Trapping in c Si Solar Cells written by Chetan Singh Solanki and published by Springer. This book was released on 2017-06-30 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers essential insights into c-Si based solar cells and fundamentals of reflection, refraction, and light trapping. The basic physics and technology for light trapping in c-Si based solar cells are covered, from traditional to advanced light trapping structures. Further, the book discusses the latest developments in plasmonics for c-Si solar cell applications, along with their future scope and the requirements for further research. The book offers a valuable guide for graduate students, researchers and professionals interested in the latest trends in solar cell technologies.

Download or read book Light Trapping with Plasmonic Back Contacts in Thin Film Silicon Solar Cells written by Ulrich Wilhelm Paetzold and published by Forschungszentrum Jülich. This book was released on 2013 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Efficiency III V Thin Film Solar Cells written by Xiaohan Li (Ph. D.) and published by . This book was released on 2015 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photon management via submicron and subwavelength nanostructures has been extensively studied over the last decade, and has become one of the most important approaches of boosting the energy conversion efficiency for thin-film photovoltaic devices. The incorporation of low dimensional nanostructures, such as GaAs/InGaAs quantum wells, into typical GaAs single-junction cells will extend the cell absorption further into the sub-GaAs bandgap region but usually results in reduced cell open-circuit voltage. As a consequence, various bandgap engineering techniques for improving the energy conversion efficiency for quantum well solar cells have been reported. This dissertation will describe studies of light trapping in multiple GaAs/InGaAs quantum well solar cells via nanostructured front side dielectric coating and back side metal/dielectric contacts, photovoltaic performance enhancement for bulk and flexible thin-film GaAs solar cells through subwavelength nanostructured antireflection coating, and bandgap engineering techniques for GaAs/InGaAs multiple quantum well solar cells. In the study of nanostructured dielectric antireflection coatings, a 5.8% increase in short-circuit current density is observed for the GaAs/In0.3Ga0.7As multiple quantum well cell coated with TiO2 nanostructured coating compared to the cell coated with conventional Si3N4 single-layer antireflection coating even in the presence of high surface recombination. Numerical simulation shows that as high as 13% increase in short-circuit current density can be achieved without surface recombination. In the study of GaAs/In0.3Ga0.7As multiple quantum well solar cells integrated with nanostructured back side metal/dielectric contacts, as high as 2.9% per quantum well external quantum efficiency is achieved, significantly surpassing the 1% per quantum well external quantum efficiency typically observed in quantum well solar cells. In both studies, two major mechanisms contributing to the increased longer wavelength quantum well absorption have been elucidated: Fabry-Perot resonances and scattering into guided optical modes. In application of subwavelength-scale optical nanostructures on bulk and flexible epitaxial lift-off GaAs solar cells for broadband, omnidirectional improvement of photovoltaic performance, 1.1× increase in short-circuit current density is observed for the bulk GaAs cell fully integrated with optical nanostructures compared to the unpatterned cell (1.09× increase in short-circuit current density for flexible epitaxial lift-off GaAs cell) at normal incidence, while 1.67× increase in short-circuit current density is observed (1.52× increase in short-circuit current density is observed for flexible epitaxial lift-off GaAs cell) at 80° angle of incidence. In the study of bandgap engineering strategies for improving the photovoltaic performance for GaAs/InGaAs multiple quantum well solar cells, a quantum well solar cell with graded quantum well depths, which has an average 18% indium concentration in quantum wells, is shown to yield improvements in both open-circuit voltage and short-circuit current density compared to a GaAs/In0.18Ga0.82As quantum well solar cell with constant quantum well depths across the intrinsic region. The results of this study suggest that such an approach can also be implemented in quantum well solar cells with more complex quantum well structures, such as ternary or quaternary quantum wells, where the conduction and valence band offsets of each quantum well can be simultaneously engineered.

Download or read book Photon Management in Solar Cells written by Ralf B. Wehrspohn and published by John Wiley & Sons. This book was released on 2015-06-08 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by renowned experts in the field of photon management in solar cells, this one-stop reference gives an introduction to the physics of light management in solar cells, and discusses the different concepts and methods of applying photon management. The authors cover the physics, principles, concepts, technologies, and methods used, explaining how to increase the efficiency of solar cells by splitting or modifying the solar spectrum before they absorb the sunlight. In so doing, they present novel concepts and materials allowing for the cheaper, more flexible manufacture of solar cells and systems. For educational purposes, the authors have split the reasons for photon management into spatial and spectral light management. Bridging the gap between the photonics and the photovoltaics communities, this is an invaluable reference for materials scientists, physicists in industry, experimental physicists, lecturers in physics, Ph.D. students in physics and material sciences, engineers in power technology, applied and surface physicists.

Download or read book Design and Fabrication of Nanostructures for Light Manipulation in Solar Cells and Microelectromechanical Systems written by Shrestha Basu Mallick and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is about nano-structuring of semiconductor devices for the improvement of their optical properties. The phenomenon of guided resonances in photonic crystal (PC) slabs will be introduced and ways of engineering these guided resonances for a variety of applications such as improved reflectivity in micro-electro-mechanical (MEMS) mirrors and increased absorption in thin-film solar cells will be discussed. The first part of the work focuses on the application of PCs in MEMS. A new process (GOPHER) that was developed to make low stress PCs out of monolithic silicon will be discussed. The advantage and ease of making multilayer PCs with Gopher will be illustrated and experimental results showing Gopher structures having spectra with broadband reflectivity (suitable for mirror applications) as well as sharp peaks (suitable for sensors) will be presented. Other applications of Gopher such as making waveguides etc., will be briefly discussed. The integration of a high quality PC mirror with a 1D resonant MEMS scanner will be demonstrated. Finally, the results of fabrication of a prototype wafer-scale encapsulated optical device will be shown. The Gopher process has a lot of potential for facilitating the integration of micro- and nano-scale photonics with CMOS circuitry. The second part of the work focuses on the application of PCs for light-trapping in solar cells. Thin-film photovoltaics has the potential to reduce cost by reducing the amount of photoactive material required and allowing for the use of material of poorer quality. Crystalline Silicon (c-Si) is an attractive material for photovoltaic cells due to its natural abundance, nearly ideal band gap, and leverage of existing process and materials knowledge. However, the poor optical absorption in the near-infrared spectral range requires the use of very efficient light trapping techniques. One such technique that is explored is to pattern the active layer into a 2D PC. Electromagnetic simulations are performed to show that an enhancement in integrated short-circuit current by a factor of 3 is possible when compared to a planar slab of equivalent volume. This is because the PC supports guided resonances into which incident radiation can couple which increases the absorption. Finally, the fabrication of an ultrathin c-Si solar cell where the active material is patterned into a square-lattice 2D PC is demonstrated. Both short-circuit current and external quantum efficiency measurements show an enhancement in optical absorption, especially at longer wavelengths. Scanning photocurrent maps confirm the improved optical absorption in the photonic structure over an unpatterned reference. Future applications of nanostructuring to thin-film cells that can be commercially realized is discussed.

Download or read book Photon Management in Solar Cells written by Ralf B. Wehrspohn and published by John Wiley & Sons. This book was released on 2016-03-09 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by renowned experts in the field of photon management in solar cells, this one-stop reference gives an introduction to the physics of light management in solar cells, and discusses the different concepts and methods of applying photon management. The authors cover the physics, principles, concepts, technologies, and methods used, explaining how to increase the efficiency of solar cells by splitting or modifying the solar spectrum before they absorb the sunlight. In so doing, they present novel concepts and materials allowing for the cheaper, more flexible manufacture of solar cells and systems. For educational purposes, the authors have split the reasons for photon management into spatial and spectral light management. Bridging the gap between the photonics and the photovoltaics communities, this is an invaluable reference for materials scientists, physicists in industry, experimental physicists, lecturers in physics, Ph.D. students in physics and material sciences, engineers in power technology, applied and surface physicists.

Download or read book Improving Light Harvesting in Dye Sensitized Solar Cells Using Hybrid Bimetallic Nanostructures written by and published by . This book was released on 2016 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we demonstrate improved light trapping in dye-sensitized solar cells (DSSCs) with hybrid bimetallic gold core/silver shell nanostructures. Silica-coated bimetallic nanostructures (Au/Ag/SiO2 NSs) integrated in the active layer of DSSCs resulted in 7.51% power conversion efficiency relative to 5.97% for reference DSSCs, giving rise to 26% enhancement in device performance. DSSC efficiencies were governed by the particle density of Au/Ag/SiO2 NSs with best performing devices utilizing only 0.44 wt % of nanostructures. We performed transient absorption spectroscopy of DSSCs with variable concentrations of Au/Ag/SiO2 NSs and observed an increase in amplitude and decrease in lifetime with increasing particle density relative to reference. Finally, we attributed this trend to plasmon resonant energy transfer and population of the singlet excited states of the sensitizer molecules at the optimum concentration of NSs promoting enhanced exciton generation and rapid charge transfer into TiO2.

Download or read book Fundamentals of Solar Cell Design written by Inamuddin and published by John Wiley & Sons. This book was released on 2021-08-24 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells are semiconductor devices that convert light photons into electricity in photovoltaic energy conversion and can help to overcome the global energy crisis. Solar cells have many applications including remote area power systems, earth-orbiting satellites, wristwatches, water pumping, photodetectors and remote radiotelephones. Solar cell technology is economically feasible for commercial-scale power generation. While commercial solar cells exhibit good performance and stability, still researchers are looking at many ways to improve the performance and cost of solar cells via modulating the fundamental properties of semiconductors. Solar cell technology is the key to a clean energy future. Solar cells directly harvest energy from the sun’s light radiation into electricity are in an ever-growing demand for future global energy production. Solar cell-based energy harvesting has attracted worldwide attention for their notable features, such as cheap renewable technology, scalable, lightweight, flexibility, versatility, no greenhouse gas emission, environment, and economy friendly and operational costs are quite low compared to other forms of power generation. Thus, solar cell technology is at the forefront of renewable energy technologies which are used in telecommunications, power plants, small devices to satellites. Aiming at large-scale implementation can be manipulated by various types used in solar cell design and exploration of new materials towards improving performance and reducing cost. Therefore, in-depth knowledge about solar cell design is fundamental for those who wish to apply this knowledge and understanding in industries and academics. This book provides a comprehensive overview on solar cells and explores the history to evolution and present scenarios of solar cell design, classification, properties, various semiconductor materials, thin films, wafer-scale, transparent solar cells, and so on. It also includes solar cells’ characterization analytical tools, theoretical modeling, practices to enhance conversion efficiencies, applications and patents.

Download or read book Nanostructured Solar Cells written by Guanying Chen and published by MDPI. This book was released on 2018-07-04 with total page 187 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Nanostructured Solar Cells" that was published in Nanomaterials

Download or read book Nanostructured Solar Cells written by Narottam Das and published by BoD – Books on Demand. This book was released on 2017-02-22 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured solar cells are very important in renewable energy sector as well as in environmental aspects, because it is environment friendly. The nano-grating structures (such as triangular or conical shaped) have a gradual change in refractive index which acts as a multilayer antireflective coating that is leading to reduced light reflection losses over broadband ranges of wavelength and angle of incidence. There are different types of losses in solar cells that always reduce the conversion efficiency, but the light reflection loss is the most important factor that decreases the conversion efficiency of solar cells significantly. The antireflective coating is an optical coating which is applied to the surface of lenses or any optical devices to reduce the light reflection losses. This coating assists for the light trapping capturing capacity or improves the efficiency of optical devices, such as lenses or solar cells. Hence, the multilayer antireflective coatings can reduce the light reflection losses and increases the conversion efficiency of nanostructured solar cells.

Download or read book Metal Nanostructures for Photonics written by Luciana Reyes Pires Kassab and published by Elsevier. This book was released on 2018-08-21 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Nanostructures for Photonics presents updates on the development of materials with enhanced optical properties and the demand for novel metal-dielectric nanocomposites and nanostructured materials. The book covers various aspects of metal-dielectric nanocomposites and metallic-nanostructures and illustrates techniques used to prepare and characterize materials and their physical properties. It focuses on three main sections, nanocomposites with enhanced luminescence properties due to contributions of metal nanoparticles hosted in photonic glasses, near and far-field optical phenomena, and the optical response of single nanoparticles that reveal quantum phenomena in the nanoscale, amongst other topics. This book will serve as an important research reference for materials scientists who want to learn more on how a range of metallic nanostructured materials are used in photonics. - Sets out the properties of a range of metal-dielectric nanostructures and nanocomposites, along with the use cases for each in photonics - Discusses the pros and cons of using different metallic nanostructures for different photonic applications - Includes case studies that illustrate how metallic nanostructures have successfully been applied in photonics

Download or read book Plasmonic and Photonic Designs for Light Trapping in Thin Film Solar Cells written by Liming Ji and published by . This book was released on 2012 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film solar cells are promising to realize cheap solar energy. Compared to conventional wafer cells, they can reduce the use of semiconductor material by 90%. The efficiency of thin film solar cells, however, is limited due to insufficient light absorption. Sufficient light absorption at the bandgap of semiconductor requires a light path more than 10x the thickness of the semiconductor. Advanced designs for light trapping are necessary for solar cells to absorb sufficient light within a limited volume of semiconductor. The goal is to convert the incident light into a trapped mode in the semiconductor layer. In this dissertation, a critical review of currently used methods for light trapping in solar cells is presented. The disadvantage of each design is pointed out including insufficient enhancement, undesired optical loss and undesired loss in carrier transport. The focus of the dissertation is light trapping by plasmonic and photonic structures in thin film Si solar cells. The performance of light trapping by plasmonic structures is dependent on the efficiency of photon radiation from plasmonic structures. The theory of antenna radiation is used to study the radiation by plasmonic structures. In order to achieve efficient photon radiation at a plasmonic resonance, a proper distribution of surface charges is necessary. The planar fishnet structure is proposed as a substitution for plasmonic particles. Large particles are required in order to resonate at the bandgap of semiconductor material. Hence, the resulting overall thickness of solar cells with large particles is large. Instead, the resonance of fishnet structure can be tuned without affecting the overall cell thickness. Numerical simulation shows that the enhancement of light absorption in the active layer is over 10x compared to the same cell without fishnet. Photons radiated from the resonating fishnet structure travel in multiple directions within the semiconductor layer. There is enhanced field localization due to interference. The short circuit current was enhanced by 13.29%. Photonic structures such as nanodomes and gratings are studied. Compared to existing designs, photonic structures studied in this dissertation exhibited further improvements in light absorption and carrier transport. The nanodome geometry was combined with conductive charge collectors in order to perform simultaneous enhancement in optics and carrier transport. Despite the increased volume of semiconductor material, the collection length for carriers is less than the diffusion length for minority carriers. The nanodome geometry can be used in the back end and the front end of solar cells. A blazed grating structure made of transparent conductive oxide serves as the back passivation layer while enhancing light absorption. The surface area of the absorber is increased by only 15%, indicating a limited increase in surface recombination. The resulting short circuit current is enhanced by over 20%. The designs presented in the dissertation have demonstrated enhancement in Si thin film solar cells. The enhancement is achieved without hurting carrier transport in solar cells. As a result, the enhancement in light absorption can efficiently convert to the enhancement in cell efficiency. The fabrication of the proposed designs in this dissertation involves expensive process such as electron beam lithography. Future work is focused on optical designs that are feasible for cheap fabrication process. The designs studied in this dissertation can serve as prototype designs for future work.