Basic physics of phototransport as manifested in thin films of In-doped CdTe

Recognizing the interesting effects associated with deep centers in II-VI semiconductors, we reveal the recombination centers map in In-doped CdTe thin films by introducing a systematic and comprehensive phototransport spectroscopy method. The method is more reliable than previous phototransport methods as it is based on a stringent self-consistency of the temperature dependencies of four phototransport properties with a given model. This limits the number of scenarios and narrows the parameter space that can account for the experimental data. We suggest that the deep centers that can account for the data in the studied CdTe system lie both above and below the Fermi level, and that their special distribution can account for some of the exotic or puzzling phenomena observed in n-type CdTe. However, the main purpose of this work is to use the analysis of the In-doped CdTe system as a vehicle for a quantitative comprehensive test of the qualitative physical-analytic ideas of Rose that have guided numerous studies of phototransport in semiconductors. Introducing here the concept of the center of gravity of the density of states distribution further extends these basic ideas.