Cadmium telluride (CdTe) thin film solar cells

Semiconductors are the basic photovoltaic materials used in inorganic solar cells. Recently, research activities have shifted progressively toward thin film solar cells utilizing polycrystalline compound semiconductors with direct band gaps and high absorption coefficients, which have enormous potential to achieve high conversion efficiency and high stability. Cadmium telluride (CdTe) has become a verified thin film solar cell material due to its unique properties. Although the exploration of CdS/CdTe heterojunction solar cells started in the early 1970s with an efficiency of around 6%, the current efficiency of the CdTe solar cell has reached 22.1% (First Solar Inc.), the leading CdTe thin film-based PV manufacturing company. Significant research has been performed with CdTe absorber material but there is still a need to enhance the conversion efficiency. Innovative design, proper methods, and cost-effective fabrication technology must be developed to attain high efficiency.