Effect of rapid thermal annealing on properties of thermally evaporated nanostructured CdTe thin film treated with CdCl2

The effects of rapid thermal annealing on properties of crystalline nanostructured CdTe films treated with CdCl2 and prepared by vacuum evaporation are described. X-ray diffraction confirmed the crystalline nature of post-treated films with high preferential orientation around 23.7°, corresponding to a (1 1 1) diffracted plane of cubic phase. Optical band gap of CdTe films increased from 1.4 eV to 1.48 eV after annealing at 500 °C for 90 s. Atomic force microscopy of annealed films revealed an increase in root mean square roughness and grain size with increased annealing time. Electrical measurements of as-grown and annealed films are consistent with p-type; film resistivity has decreased significantly with increased annealing time.