The results of an experimental study of photoelectric characteristics of two-layer photoresistors based on р-Cd x Hg1–xTe (x = 0.24−0.28) with a thin near-surface layer of n-type obtained by treatment in atmospheric gas plasma are presented. It is shown that the presence of a potential barrier between the p- and n-regions causes high photosensitivity and speed of operation of such photoresistors at T = 77 K