In recent years, the thin films of semiconductors and their junctions have received much attention due to their potential photovoltaic and optoelectronic applications. This book devoted the chapters to discuss thin film growth with background theory, included many experimental details on sample preparation and measurements, and studies on thermally deposited thin films of cadmium selenide and their Schottky barrier junctions and heterojunctions. Attempt has been made to investigate the structural, morphological, optical and electrical properties (in dark and under illumination) of CdSe thin films prepared at optimised growth conditions. Schottky barriers of CdSe films with different barrier metals and their heterojunctions with different semiconductors of suitable band gap have been prepared and their current-voltage characteristics are investigated from the stand point of photovoltaic applications. This book presents the reader with promising findings of these studies useful in photovoltaic applications and solar cell technology.