Solar cell is a device that converts solar energy into electrical energy. This book focuses on solar cells based on silicon wafers which is the major substance used in today's photovoltaics. It presents latest results of researches aimed at increasing efficiency, lowering consumption of materials and decreasing cost of wafer-based silicon solar cells, as well as modern means of research and testing of the devices. Light trapping arrangement in c-Si and mc-Si solar cells, design criteria for spacecraft solar arrays and solar-energy conversion as a function of the geometric-concentration factor are some issues discussed within the book. It also elucidates topics such as LBIC method for characterization of solar cells, non-idealities in the I-V characteristic of the PV generators, a new model for extracting the physical parameters of solar cells, among others.