Reversible transition from sensitive to nonsensitive state in the films of CdxPb1-xS solid solutions

It is shown experimentally that UV radiation in vacuum causes degradation of photosensitivity of polycrystalline films CdxPb1-xS (using x ∼ 0.06 composition). Three stages of degradation are detected: 1) dark current Id and photo current Ip decrease at Ip/Id ∼ const; 2) current Ip decreases at Id ∼ const and Ip ∼ Ip/Id; 3) Id increases at Ip ∼ const and Ip/Id ∼ Id-1. Quick reduction of photosensitivity when damp and ozonized air interacting is observed. Change in activation barriers for dark electrical resistance (φR) and the constant of a photoresponse time (φτ) is established according to temperature dependences. The conditions for sum conservation ξ=φR+φτ are determined when dark and photo current changing. Step change ξ in transition from the sensitive state to nonsensitive and vice versa is determined. The explanation for the dependences detected is given within the scope of the model taking into account inverse bending of zones on the surface