Download or read book Light trapping Enhancement in Thin Film Solar Cells with Photonic Crystals written by Dayu Zhou and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Light Trapping in Thin Film Solar Cells Using Textured Photonic Crystal written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A solar cell includes a photoactive region that receives light. A photonic crystal is coupled to the photoactive region, wherein the photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light.
Download or read book Thin film Silicon Solar Cells written by Xing Sheng (Ph. D.) and published by . This book was released on 2012 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photovoltaic technology has been attracting widespread attention because of its effective energy harvest by directly converting solar energy into electricity. Thin-film silicon solar cells are believed to be a promising candidate for further scaled-up production and cost reduction while maintaining the advantages of bulk silicon. The efficiency of thin-film Si solar cells critically depends on optical absorption in the silicon layer since silicon has low absorption coefficient in the red and near-infrared (IR) wavelength ranges due to its indirect bandgap nature. This thesis aims at understanding, designing, and fabricating novel photonic structures for efficiency enhancement in thin-film Si solar cells. We have explored a previously reported a photonic crystal (PC) based structure to improve light absorption in thin-film Si solar cells. The PC structure combines a dielectric grating layer and a distributed Bragg reflector (DBR) for effcient light scattering and reflection, increasing light path length in the thin-film cell. We have understood the operation principles for this design by using photonic band theories and electromagnetic wave simulations. we discover that this DBR with gratings exhibit unusual light trapping in a way different from metal reflectors and photonic crystals. The light trapping effects for the DBR with and without reflector are numerically investigated. The self-assembled anodic aluminum oxide (AAO) technique is introduced to non- lithographically fabricate the grating structure. We adjust the AAO structural parameters by using different anodization voltages, times and electrolytes. Two-step anodization is employed to obtain nearly hexagonal AAO pattern. The interpore periods of the fabricated AAO are calculated by fast Fourier transform (FFT) analysis. We have also demonstrated the fabrication of ordered patterns made of other materials like amorphous Si (a-Si) and silver by using the AAO membrane as a deposition mask. Numerical simulations predict that the fabricated AAO pattern exhibits light trapping performance comparable to the perfectly periodic grating layer. We have implemented the light trapping concepts combining the self-assembled AAO layer and the DBR in the backside of crystalline Si wafers. Photoconductivity measurements suggest that the light absorption is improved in the near-IR spectral range near the band edge of Si. Furthermore, different types of thin-film Si solar cells, including a-Si, mi- crocrystalline Si ([mu]-Si) and micromorph Si solar cells, are investigated. For demonstration, the designed structure is integrated into a 1:5 [mu]m thick [mu]c-Si solar cell. We use numerical simulations to obtain the optimal structure parameters for the grating and the DBR, and then we fabricate the optimized structures using the AAO membrane as a template. The prototype devices integrating our proposed backside structure yield a 21% improvement in efficiency. This is further verified by quantum efficiency measurements, which clearly indicate stronger light absorption in the red and near-IR spectral ranges. Lastly, we have explored the fundamental light trapping limits for thin-film Si solar cells in the wave optics regime. We develop a deterministic method to optimize periodic textures for light trapping. Deep and high-index-contrast textures exhibit strong anisotropic scattering that is outside the regime of validity of the Lambertian models commonly used to describe texture-induced absorption enhancement for normal incidence. In the weak ab- sorption regime, our optimized surface texture in two dimensions (2D) enhances absorption by a factor of 2.7[pi]n, considerably larger than the classical [pi]n Lambertian result and exceeding by almost 50% a recent generalization of Lambertian model for periodic structures in finite spectral range. Since the [pi]n Lambertian limit still applies for isotropic incident light, our optimization methodology can be thought of optimizing the angle/enhancement tradeoff for periodic textures. Based on a modified Shockley-Queisser theory, we conclude that it is possible to achieve more than 20% efficiency in a 1:5 [mu]m thick crystalline Si cell if advanced light trapping schemes can be realized.
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 Light Trapping Designs for Thin Silicon Solar Cells written by James Mutitu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the increasing scarcity of fossil fuels and a general concern for the environmental impacts of carbon emissions and hazardous radiation, the need for clean renewable energy sources has become not only a national priority but also an issue of national security. Renewed interest in the development of solar electricity has led to the development of new avenues that address the issues of cost and efficiency associated with photovoltaics. One of the prominent approaches being explored is thin film solar cell technology, which offers prospects of lower material costs and increases the adaptability of solar cell design. The goal of this work is to increase the efficiency and versatility of thin film solar cell devices through the development of improved light trapping schemes. Enhanced light trapping schemes increase the absorption of light within solar cell devices and thereby increase the efficiency and ultimately reduce the cost per watt of energy produced. This thesis introduces the fundamental ideas behind the science of light trapping in thin silicon solar cells. The specific approach involves enhancing the light trapping capabilities, of the thin solar cells, by incorporating photonic device engineering concepts which include photonic crystals, diffraction gratings and antireflective coatings. These concepts are then used to develop novel light trapping designs that are applied to stand alone and multiple junction thin silicon solar cells. The new designs, that are developed, incorporate one dimensional photonic crystals as band pass filters that reflect short light wavelengths (400-1100 nm) and transmit longer wavelengths(1100 -1800 nm) at the interface between two adjacent cells. In addition, nano structured diffraction gratings that cut into the photonic crystal layers are incorporated to redirect incoming waves and hence increase the optical path length of light within the solar cells.
Download or read book Diffractive Optics for Thin Film Silicon Solar Cells written by Christian Stefano Schuster and published by Springer. This book was released on 2016-09-26 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis introduces a figure of merit for light trapping with photonic nanostructures and shows how different light trapping methods compare, irrespective of material, absorber thickness or type of nanostructure. It provides an overview of the essential aspects of light trapping, offering a solid basis for future designs. Light trapping with photonic nanostructures is a powerful method of increasing the absorption in thin film solar cells. Many light trapping methods have been studied, but to date there has been no comprehensive figure of merit to compare these different methods quantitatively. This comparison allows us to establish important design rules for highly performing structures; one such rule is the structuring of the absorber layer from both sides, for which the authors introduce a novel and simple layer-transfer technique. A closely related issue is the question of plasmonic vs. dielectric nanostructures; the authors present an experimental demonstration, aided by a detailed theoretical assessment, highlighting the importance of considering the multipass nature of light trapping in a thin film, which is an essential effect that has been neglected in previous work and which allows us to quantify the parasitic losses.
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 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 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.
Download or read book High Efficiency Thin Film Silicon Solar Cells with Novel Light Trapping written by Lirong Zeng (Ph. D.) and published by . This book was released on 2008 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) To prove the theory on the intended application, top-contacted thin film Si solar cells integrated with the TPC back reflector are successfully fabricated using Si-on-insulator material through an active layer transfer technique. All cells exhibit strong absorption enhancement, similar to that predicted by simulation. The 5 [mu]m thick cells gained 19% short circuit current density improvement, despite machine problems during fabrication. The textured photonic crystal back reflector design can be applied directly to single and poly-crystalline Si solar cells, and its principle is broadly applicable to other materials systems.
Download or read book Photonic Crystal Metasurface Optoelectronics written by and published by Academic Press. This book was released on 2019-07-10 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photonic Crystal Metasurface Optoelectronics, Volume 101, covers an emerging area of nanophotonics that represents a new range of optoelectronic devices based on free-space coupled photonic crystal structures and dielectric metasurfaces. Sections in this new release include Free-space coupled nanophotonic platforms, Fano resonances in nanophotonics, Fano resonances in photonic crystal slabs, Transition from photonic crystals to dielectric metamaterials, Photonic crystals for absorption control and energy applications, Photonic crystal membrane reflector VCSELs, Fano resonance filters and modulators, and Fano resonance photonic crystal sensors. - Presents the latest in an emerging area of research with great potentials for research and commercialization - Includes sections written by world leading researchers in the field
Download or read book Recent Trends in Materials and Devices written by Vinod Kumar Jain and published by Springer. This book was released on 2016-10-20 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the International Conference on Recent Trends in Materials and Devices, which was conceived as a major contribution to large-scale efforts to foster Indian research and development in the field in close collaboration with the community of non-resident Indian researchers from all over the world. The research articles collected in this volume - selected from among the submissions for their intrinsic quality and originality, as well as for their potential value for further collaborations - document and report on a wide range of recent and significant results for various applications and scientific developments in the areas of Materials and Devices. The technical sessions covered include photovoltaics and energy storage, semiconductor materials and devices, sensors, smart and polymeric materials, optoelectronics, nanotechnology and nanomaterials, MEMS and NEMS, as well as emerging technologies.
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 Enhancement of Thin film Solar Cell Efficiency by Light Trapping written by Takumi Yoshida and published by . This book was released on 1998 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Characterization Techniques for Thin Film Solar Cells written by Daniel Abou-Ras and published by John Wiley & Sons. This book was released on 2016-07-13 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on advanced characterization methods for thin-film solar cells that have proven their relevance both for academic and corporate photovoltaic research and development. After an introduction to thin-film photovoltaics, highly experienced experts report on device and materials characterization methods such as electroluminescence analysis, capacitance spectroscopy, and various microscopy methods. In the final part of the book simulation techniques are presented which are used for ab-initio calculations of relevant semiconductors and for device simulations in 1D, 2D and 3D. Building on a proven concept, this new edition also covers thermography, transient optoelectronic methods, and absorption and photocurrent spectroscopy.
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.
