The Physics of High-Efficiency Thin-Film III-V Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Physics of High-Efficiency Thin-Film III-V Solar Cells write by Roger E. Welser. This book was released on 2015. The Physics of High-Efficiency Thin-Film III-V Solar Cells available in PDF, EPUB and Kindle. The Physics of High-Efficiency Thin-Film III-V Solar Cells.
High Efficiency III/V Thin Film Solar Cells
High Efficiency III/V Thin Film Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook High Efficiency III/V Thin Film Solar Cells write by Xiaohan Li (Ph. D.). This book was released on 2015. High Efficiency III/V Thin Film Solar Cells available in PDF, EPUB and Kindle. 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.
Solar Cells
Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Solar Cells write by Augustin McEvoy. This book was released on 2012-12-31. Solar Cells available in PDF, EPUB and Kindle. Enormous leaps forward in the efficiency and the economy of solar cells are being made at a furious pace. New materials and manufacturing processes have opened up new realms of possibility for the application of solar cells. Crystalline silicon cells are increasingly making way for thin film cells, which are spawning experimentation with third-generation high-efficiency multijunction cells, carbon-nanotube based cells, UV light for voltage enhancement, and the use of the infrared spectrum for night-time operation, to name only a few recent advances. This thoroughly updated new edition of Markvart and Castaner’s Solar Cells, extracted from their industry standard Practical Handbook of Photovoltaics, is the definitive reference covering the science and operation, materials and manufacture of solar cells. It is essential reading for engineers, installers, designers, and policy-makers who need to understand the science behind the solar cells of today, and tomorrow, in order to take solar energy to the next level. A thorough update to the definitive reference to solar cells, created by a cast of international experts from industry and academia to ensure the highest quality information from multiple perspectives Covers the whole spectrum of solar cell information, from basic scientific background, to the latest advances in materials, to manufacturing issues, to testing and calibration. Case studies, practical examples and reports on the latest advances take the new edition of this amazing resource beyond a simple amalgamation of a vast amount of knowledge, into the realm of real world applications
High-Efficiency Solar Cells
High-Efficiency Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook High-Efficiency Solar Cells write by Xiaodong Wang. This book was released on 2013-11-01. High-Efficiency Solar Cells available in PDF, EPUB and Kindle. As part of the effort to increase the contribution of solar cells (photovoltaics) to our energy mix, this book addresses three main areas: making existing technology cheaper, promoting advanced technologies based on new architectural designs, and developing new materials to serve as light absorbers. Leading scientists throughout the world create a fundamental platform for knowledge sharing that combines the physics, materials, and device architectures of high-efficiency solar cells. While providing a comprehensive introduction to the field, the book highlights directions for further research, and is intended to stimulate readers’ interest in the development of novel materials and technologies for solar energy applications.
High-efficiency Thin-film Crystalline Solar Cells
High-efficiency Thin-film Crystalline Solar Cells - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook High-efficiency Thin-film Crystalline Solar Cells write by Yangsen Kang. This book was released on 2015. High-efficiency Thin-film Crystalline Solar Cells available in PDF, EPUB and Kindle. Thin-film high-efficiency crystalline solar cells are expected to play a significant role as a greener, renewable energy source of the future. Such cells have been extensively studied over the past 10 years. Most of this research focused on developing thinner cells to reduce material usage and improving the optical absorption within the thin absorber. Most recently, the active semiconductor layer can be 10 -- 100 times thinner than conventional solar cells by advanced light trapping. However, an improvement in efficiency in thin-film solar cells had not been previously appreciated and is an equally if not more important enhancement of the cells in addition to materials cost saving. This dissertation presents the device physics of thin-film crystalline solar cells and demonstrates the key design principle to achieve higher efficiency by improving two important parameters: open circuit voltage (Voc) and short circuit current (Jsc). The first part of this thesis focuses on achieving high Voc in thin-film c-Si solar cells and demonstrate the voltage enhancement in thin-film Si solar cells in both theoretical simulation and experimental demonstration. Theoretically, thin cells can significantly increase the carrier concentration by confining photo-carriers into a smaller active region and decrease the recombination by reducing the volume of the active region. This results in higher Voc and efficiency. Experimentally, the first Voc enhancement in thin-film solar cells is demonstrated. The 5 æm thick Si cell achieved a Voc of 649 mV, which is superior to the Voc of any other thin-film (sub-25-æm) Si solar cells reported to date. To further improve efficiency, a carrier selective contact of TiO2/Si was developed to reduce the high carrier recombination at the metal contacts associated with the high carrier centration in thin films. Such a contact demonstrates a contact recombination reduction of 33% and a Voc enhancement of 10 mV compared to a conventional metal contact. The second part mainly discusses high Jsc by applying nanoscale light trapping structures to thin-film c-Si and III-V solar cells. Given the challenges in obtaining low surface recombination and high efficiency in nanostructured solar cells, we demonstrated a nanowindow solar cell design with dielectric or wide bandgap semiconductor material that can overcome these challenges. A SiNx nanostructured dielectric layer can provide both light tapping and surface passivation for Si. A thin Si film with such SiNx layer exhibits
