Structure and properties of sputter-deposited CdTe

Abstract
CdTe films were sputter deposited in thicknesses of 2 to 10 μm using systematically selected deposition conditions. Crystal structure was controllably varied from sharp hexagonal (wurtzite), to highly faulted, to sharp cubic (sphalerite). Electrical resistivity was controllably varied from 10 4 to 108 Ω.cm for p-type material and from 106 to 108 Ω.cm for n-type films. Infrared transmission characteristics for wavelengths near the band edge were controllably varied from highly transparent to highly absorptive. The variation in both the structure and properties of the deposited films was shown to result from the influence of sputter deposition parameters on film composition (stoichiometry). Deposition parameters which influence grain size in the polycrystalline films were established, and grain sizes ranging from 0.2 to 3 μm were produced. Control of the electrical properties of the films by doping with several different acceptor impurities was only slightly successful