Photoluminescence investigation of new narrow-gap semiconductor materials Hg/sub 1-x-y/Zn/sub x/Cd/sub y/Te

The defect and impurity states in narrow-gap alloys Hg/sub 1-x-y/Zn/sub x/Cd/sub y/Te n- and p-types have been studied by low-temperature photoluminescence. In photoluminescence spectra of p-type samples two new bands were observed in addition to bands which were observed in photoluminescence spectra of n-type material. The results of temperature dependence of the intensity of photoluminescence bands demonstrated that these additional bands are connected with twofold charged states of one impurity-vacancy of Hg atom. It was found that at helium temperatures the band to band transition involved recombination of excitons bound to tails of bands conditioned by fluctuations of composition in quaternary compound material. The value of these tails obtained from experimental data in consistent with theoretical calculations. (author)