BaCl₂ an efficient replacement of CdCl₂ treatment step for thermally deposited CdTe thin film

Cadmium telluride (CdTe), a II–VI compound semiconductor has long been identified as suitable absorber material. A central part of the fabrication process includes the coating of cadmium chloride on CdTe thin films. Coating of CdCl₂ has severe disadvantages; it is expensive and a water-soluble source of toxic cadmium ions, making it extremely environment unfriendly. We report the development of barium chloride (BaCl₂) as an efficient coating material for CdTe thin film. We have demonstrated that CdTe thin films can be prepared using BaCl₂ which is non-toxic and costs effective and may replace CdCl₂. Coating of BaCl₂ helps distribution of acceptor like impurities resulting in p-conversion of the cadmium telluride layer. The structural, electrical and optical properties of BaCl₂ coated CdTe thin films have been investigated and results are presented. (paper)