The world of nanotechnology has opened a vast array of novel frontiers in materials science, by the exploitation of the properties and phenomena at the nanometer scale. After transistors, also other devices will enter the nanoscale era. Technologies based on semiconducting and/or organic materials have moved from a few empirical examples to a booming science-based activity. Physics at nanoscale becomes the science used for new device improvements. Solar cells are no exception to that. This book on nanophysics of photovoltaic cells thus comes at the right moment. Such a book will support research efforts in numerous laboratories where the solar cells of tomorrow are designed. The reader will be happy to find chapters on various topics, such as thermodynamics, photonics and electronics of dye-sensitized, electrochemical, nanostructured, polymer and organic materials. Light concentration, photoluminescence, intermediate-band absorption, photon conversion, and quantum confinement are discussed. The present book will surely be of great value for all scientists and engineers involved in the development of future solar cells.