Investigation of fast surface states in photosensitive wide-block pCdTe films

In this paper the fast surface states (FSS) have been investigated in wide-block pCdTe films. It was show that FSS states are predominantly formed at the boundary between the metal substrate (Mo) and the pCdTe film. It was established that the origin and spectra of FSS (τ=2·10-6-10-4s) are defined by chemical composition and structure of the boundary between the semiconductor (pCdTe) and the dielectric (high-resistive fine-grained oxide layer), which is formed during synthesis of the pCdTe films on the surface of metal substrate (Mo). By investigation of the photoconductivity relaxation processes as a function of temperature it was shown which of FSS are responsible for the recombination processes and which of them for establishing the quasi-equilibrium between the trap levels and the valence band pCdTe. (author)