Large grain CdTe thin films on Sb–Bi alloy‐coated Ta substrates

Description is given of the preparation and structural properties of thin CdTe films deposited on two Sb–Bi alloys with compositions of 60% and 70% by weight of Sb on Ta substrates, at temperatures just below that of the melting temperature of the alloys, 380° and 430 °C, respectively. The Sb–Bi alloy films grow with an (003) preferential orientation that matches the (111) plane of CdTe, and are expected to provide low‐resistance Ohmic contacts to p‐type CdTe in solar cell applications. The grain size of the CdTe films was about 2 μm when deposited at 350 °C on the 60% Sb alloy; after vacuum annealing of the deposited film for 10–15 h at 350 °C, the grain size of both the Sb–Bi film and of the CdTe film increased to about 20 μm. With controlled conductivity, CdTe films deposited in this way should make ideal solar cell components.