Thin-film solar cells potentially offer a suitable technology for solving the energy production problem with an environmentally friendly method. Additionally, thin film technologies show advantages over their bulk-semiconductor counterparts due to their lighter weight, flexible shape, device fabrication schemes and low cost in large-scale industrial production. This book provides an international perspective on the latest research in this rapidly expanding field, as well as presenting a wide range of scientific and technological aspects on thin film semiconductors, deposition technologies, basic properties and device physics of high-efficiency thin film solar cells.