Optical absorption in layered monocrystals of A2B23C46 type chalcogenides

Edge absroption spectra of layered monocrystals of semiconductor compounds ZnIn2S4 (2), HgInGaS4 and the main photoelectric characteristics of specially doped samples of ZnIn2S4 (3) < Mn > are investigated. Directly resolved optical transitions with the width of forbidden zone at 295 K of 2.74 K and 2.35...2.41 eV respectively have been detected for the first time. In the samples ZnIn2S4 (3) < Mn > a shift of photocurrent maximum and transition point from one photosensitivity to another in lux-ampere characteristic, variation of recombination type depending on impurity concentration have been revealed. A model for the experimental results interpretation is suggested. 15 refs.; 4 figs.; 2 tabs