Widespread adoption of photovoltaics (PV) as an alternative electricity source will be predicated upon improvements in price performance compared to traditional power sources. Solution processing of thin-film PV is one promising way to reduce the capital expenditure (CAPEX) of manufacturing solar cells. However, it is imperative that a shift to solution processing does not come at the expense of device performance. One particularly problematic parameter for thin-film PV has historically been the open-circuit voltage (VOC). As such, there is a pressing need for characterization tools that allow us to quickly and accurately evaluate the potential performance of solution-processed PV absorber layers. This work describes recent progress in developing photoluminescence (PL) techniques for probing optoelectronic quality in semiconductors. We present a generalized model of absorption that encompasses ideal direct-gap semiconductor absorption and various band tail models. This powerful absorption model is used to fit absolute intensity PL data and extract quasi-Fermi level splitting (maximum attainable VOC) for a variety of PV absorber technologies. This technique obviates the need for full device fabrication to get feedback on optoelectronic quality of PV absorber layers and has expedited materials exploration. We then use this absorption model to evaluate the thermodynamic losses due to different band tail cases and estimate tail losses in Cu2ZnSn(S,Se)4 (CZTSSe). The effect of sub-bandgap absorption on PL quantum yield (PLQY) and voltage is elucidated, and new analysis techniques for extracting VOC from PLQY are validated that reduce computation time and provide us even faster feedback on material quality. We then use PL imaging to develop a mechanism describing the degradation of solution-processed CH3NH3PbI3 films under applied bias and illumination.

The first comprehensive book on thin-film solar cells, potentially a key technology for solving the energy production problem in the 21st century in an environmentally friendly way. It covers a wide range of scientific and technological aspects of thin film semiconductors - deposition technologies, growth mechanisms and the basic properties of amorphous and nano-crystalline silicon - as well as the optimum design theory and device physics of high-efficiency solar cells, especially of single-junction and multi-junction solar cells. The development of large-area solar cell modules using single and multi-junction solar cells is also considered. Examples of recent photovoltaic systems are presented and analysed.

PHYSICS OF THIN-FILM PHOTOVOLTAICS Tackling one of the hottest topics in renewables, thin-film photovoltaics, the authors present the latest updates, technologies, and applications, offering the most up-to-date and thorough coverage available to the engineer, scientist, or student. It appears rather paradoxical that thin-film photovoltaics (PVs) are made of materials that seem unacceptable from the classical PV perspective, and yet they often outperform classical PV. This exciting new volume solves that paradox by switching to a new physics paradigm. Many concepts here fall beyond the classical PV scope. The differences lie in device thinness (microns instead of millimeters) and morphology (non-crystalline instead of crystalline). In such structures, the charge carriers can reach electrodes without recombination. On the other hand, thin disordered structures render a possibility of detrimental lateral nonuniformities (“recombination highways”), and their energy spectra give rise to new recombination modes. The mechanisms of thermal exchange and device degradation are correspondingly unique. The overall objective of this book is to give a self-contained in-depth discussion of the physics of thin-film systems in a manner accessible to both researchers and students. It covers most aspects of the physics of thin-film PV, including device operations, material structure and parameters, thin-film junction formation, analytical and numerical modeling, concepts of large area effects and lateral non-uniformities, physics of shunting (both shunt growth and effects), and device degradation. Also, it reviews a variety of physical diagnostic techniques proven with thin-film PV. Whether for the veteran engineer or the student, this is a must-have for any library. This outstanding new volume: Covers not only the state-of-the-art of thin-film photovoltaics, but also the basics, making this volume useful not just to the veteran engineer, but the new-hire or student as well Offers a comprehensive coverage of thin-film photovoltaics, including operations, modeling, non-uniformities, piezo-effects, and degradation Includes novel concepts and applications never presented in book format before Is an essential reference, not just for the engineer, scientist, and student, but the unassuming level of presentation also makes it accessible to readers with a limited physics background Is filled with workable examples and designs that are helpful for practical applications Is useful as a textbook for researchers, students, and faculty for understanding new ideas in this rapidly emerging field Audience: Industrial professionals in photovoltaics, such as engineers, managers, research and development staff, technicians, government and private research labs; also academic and research universities, such as physics, chemistry, and electrical engineering departments, and graduate and undergraduate students studying electronic devices, semiconductors, and energy disciplines

Photovoltaic (PV) solar energy is expected to be the world's largest source of electricity in the future. To enhance the long-term reliability of PV modules, a thorough understanding of failure mechanisms is of vital importance. In addition, it is important to address the potential downsides to this technology. These include the hazardous chemicals needed for manufacturing solar cells, especially for thin-film technologies, and the large number of PV modules disposed of at the end of their lifecycles. This book discusses the reliability and environmental aspects of PV modules.

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.

Photovoltaics, the direct conversion of sunlight to electricity, is now the fastest growing technology for electricity generation. Present "first generation" products use the same silicon wafers as in microelectronics. "Second generation" thin-films, now entering the market, have the potential to greatly improve the economics by eliminating material costs. Martin Green, one of the world’s foremost photovoltaic researchers, argues in this book that "second generation" photovoltaics will eventually reach its own material cost constraints, engendering a "third generation" of high performance thin-films. The book explores, self-consistently, the energy conversion potential of advanced approaches for improving photovoltaic performance and outlines possible implementation paths.

The distribution of the electrostatic potential in and between the materials in Cu(In,Ga)Se2 thin-film solar cells has a major impact on their superior performance. This thesis reported on the nanoscale imaging of the electrostatic potential on untreated cross sections of operating Cu(In,Ga)Se2 solar cells using Kelvin probe force microscopy.