Properties of CdTe Films Heat-Treated in Te Vapour

Abstract

Upon heat treatment in Te vapour , CdTe films formed by compound evaporation showed a decrease in resistivity of four orders, while an increase in grain size was detected by SEM and XRD. The diffusion length, Hall mobility, lifetime and density of holes in as-deposited films was determined from the PME effect. XRD and XPS detected no free Te in films before or after heat-treatment, while SIMS indicated the inclusion of at least 16 impurities from the source material. CdS/CdTe photovoltaic cells based upon these films showed an increase in efficiency of one order.