In this work, we discuss a new fundamental PID mechanism that has not been reported. We developed in-situ Kelvin probe force microscopy to monitor the potential evolution at nanometer scale under high-voltage stress. We observed large-area junction degradation during the stressing and junction recovery by heat treatment from the same location. Electron-beam induced current (EBIC) results support the large-area damage, which has a much lower collected current (dark region) and has an abrupt transition between the bright and dark areas, in addition to local shunts. Transmission electron microscopy does not find stacking faults in the dark-EBIC region. Furthermore, time-of-flight secondary-ion mass spectrometry indicates that the large-area damage correlates with more sodium content. The consistent results shed new light on PID mechanisms that are essentially different from the widely reported local-junction shunts.

The early chapters comprehensively review the optical and transport properties of silicon. Light trapping is described in detail. Limits on the efficiency of silicon cells are discussed as well as material requirements necessary to approach these limits. The status of current approaches to passifying surfaces, contacts and bulk regions is reviewed. The final section of the book describes the most practical approaches to the fabrication of high-efficiency cells capable of meeting the efficiency targets for both concentrated and non-concentrated sunlight, including a discussion of design and processing approaches for non-crystalline silicon.

Solar Cell Device Physics offers a balanced, in-depth qualitative and quantitative treatment of the physical principles and operating characteristics of solar cell devices. Topics covered include photovoltaic energy conversion and solar cell materials and structures, along with homojunction solar cells. Semiconductor-semiconductor heterojunction cells and surface-barrier solar cells are also discussed. This book consists of six chapters and begins by introducing the reader to the basic physical principles and materials properties that are the foundations of photovoltaic energy conversion, with emphasis on various photovoltaic devices capable of efficiently converting solar energy into usable electrical energy. The electronic and optical properties of crystalline, polycrystalline, and amorphous materials with both organic and inorganic materials are considered, together with the manner in which these properties change from one material class to another and the implications of such changes for photovoltaics. Generation, recombination, and bulk transport are also discussed. The two mechanisms of photocarrier collection in solar cells, drift and diffusion, are then compared. The remaining chapters focus on specific solar cell device classes defined in terms of the interface structure employed: homojunctions, semiconductor-semiconductor heterojunctions, and surface-barrier devices. This monograph is appropriate for use as a textbook for graduate students in engineering and the sciences and for seniors in electrical engineering and applied physics, as well as a reference book for those actively involved in solar cell research and development.

A bird's-eye view of the developmental trends and problems of recent photovoltaics is presented. The worldwide effort to develop high-efficiency low-cost PV modules, making use of most efficient solar cells and clever low-cost solar concentrators is described.

This book reviews the current status of semiconductor materials for conversion of sunlight to electricity, and highlights advances in both basic science and manufacturing. Photovoltaic (PV) solar electric technology will be a significant contributor to world energy supplies when reliable, efficient PV power products are manufactured in large volumes at low cost. Expert chapters cover the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally friendly copper zinc tin sulfide selenides. The latest methods for synthesis and characterization of solar cell materials are described, together with techniques for measuring solar cell efficiency. Semiconductor Materials for Solar Photovoltaic Cells presents the current state of the art as well as key details about future strategies to increase the efficiency and reduce costs, with particular focus on how to reduce the gap between laboratory scale efficiency and commercial module efficiency. This book will aid materials scientists and engineers in identifying research priorities to fulfill energy needs, and will also enable researchers to understand novel semiconductor materials that are emerging in the solar market. This integrated approach also gives science and engineering students a sense of the excitement and relevance of materials science in the development of novel semiconductor materials. · Provides a comprehensive introduction to solar PV cell materials · Reviews current and future status of solar cells with respect to cost and efficiency · Covers the full range of solar cell materials, from silicon and thin films to dye sensitized and organic solar cells · Offers an in-depth account of the semiconductor material strategies and directions for further research · Features detailed tables on the world leaders in efficiency demonstrations · Edited by scientists with experience in both research and industry