Due to limitation of fossil fuels, renewable energy especially solar energy has made an enormous attention for its large availability, low-cost and environment friendly nature. The most promising candidate is polycrystalline Cadmium Telluride (CdTe) thin-film solar cell because of its superb photovoltaic characteristics as a thin-film absorber as well as low fabrication cost. The main focus of this book is to contribute in developing novel techniques to achieve higher efficiency approaching towards the attainable energy conversion efficiency. Efforts are made to reduce CdTe absorber layer thickness and a ZnTe layer as back surface field (BSF) with optimum doping density which substantiates sensible energy conversion efficiency. In this wok, it is demonstrated that our experimental outcomes attaining higher conversion efficiency along with commercial potential, economic feasibility as well as environmental friendliness.