Application of tin-doped cadmium oxide films in CdTe/CdS solar cells

Transparent conducting tin-doped cadmium oxide films (CdO:Sn) have been deposited by metalorganic chemical vapor deposition (MOCVD) at atmospheric pressure. The effects of various deposition parameters, such as the partial pressures of DMCd and TMT, and substrate temperature, on the electrical and optical properties of as-deposited films were studied. A sheet resistance of 14 similar to 17 Omega /sq was obtained for a film thickness of 125 nm. The high conductivity of the as-deposited films was due to their high carrier concentrations. The transmission of the films in the visible range (500-850 nm) was found to be high (80 similar to 95%). Both electrical and optical properties of the as-deposited films improved after annealing in H-2 or He ambient. CdTe/CdS solar cells have been fabricated using CdO:Sn as the front contact and a conversion efficiency of 14.3% has been obtained.