Effect of pulsed laser irradiation on the photoconductivity of polycrystalline CdTe films

Polycrystalline CdTe films were prepared by molecular-beam deposition onto sapphire and glassceramic substrates at 670 K. The photoelectric behavior of the films (dependence of photoconductivity on incident light intensity and spectral response of photocurrent) was found to depend on grain size. The photoresponse of the fine-grained films in the intrinsic-absorption range and that of the coarse-grained films in the intrinsic- and impurity-absorption ranges increase as a result of above-gap irradiation with 20-ns laser pulses. The dependences of photoconductivity on incident intensity for the coarse-grained films are similar to those for CdTe single crystals. The grain boundaries in fine-grained CdTe films play an important part in the generation and recombination of charge carriers.