The increase in world energy consumption and limited availability of fossil fuels has made the renewable energy sources the most discussed issue these days.There are several renewable energy sources such as solar, wind, rain and geothermal energy etc.Among, these, solar energy is identified as the best renewable energy source due to its longevity, cost effectiveness and clean properties.Harnessing of solar energy for significant technological applications is another cause of great concern as it require materials that have a high ability of solar energy collection and conversion. Therefore a wide variety of materials such as Si, CdSe, CdS, CuInSe2 etc have been used for fabrication of solar cells with high conversion efficiency. Although silicon with 22 % efficiency has been and remains the traditional solar cell material of choice but its high cost and fragility reduces its residential applications.Cadmium based solar cells are also considered in commercial modules due to their high efficiency of upto 19%, but highly toxic nature of Cd limits its applications.In this book Silver based ternary chalcopyrite (AIS)films are explored for possible photovoltaic applications.