Solar energy being the most important source of energy, several technologies have been developed for utilization of solar energy. Photovoltaic devices popularly known as solar cells convert solar energy into the electricity which is the most convenient form of energy. Hence thin film photovoltaic technologies are being developed. Thin film solar cell concept is being persued since the inception of photovoltaic devices. For making thin film solar cells many technologies such as CVD, Spray Pyrolysis, Glow Discharge, CBD, Electrodeposition, etc. have been used in the laboratories. The book proposes the simple Chemical Bath Deposition (CBD) technique for synthesizing thin films. The experimental results on synthesis and structural, optical, electrical properties of Cd(S,Se), CdZnS thin films and p-Cu2Se/n-CuBiSe2 hetero- junction thin films for solar cell applications by CBD are discussed. This book will be helpful for students, teachers and researchers for synthesis of thin films by using simple Chemical Bath Deposition technique.