Picosecond photoconductivity of CdSe and CdTe thin films

Abstract Transient photoconductivity in polycrystalline CdSe and CdTe films deposited on pyro-ceramic or SiO 2 substrates has been investigated. The average grain size was 0.1–0.2 μm. It has been found that recombination centers located in the intercrystalline and surface regions control the photoconductivity until the nonequilibrium carrier concentration reaches 10 18 cm 3 . It is proposed that Auger recombination via local levels determines the lifetime at higher densities of carriers in CdSe . An Auger recombination coefficient equal to 2×10 29 cm 6 s -1 is determined.