Nature of solid solutions in Ag2S(Se)–Ga2S(Se)3–In2S(Se)3 (820 K) were discussed.
Crystal structures of ternary and quaternary compounds were discussed.
Specific conductivity, optical properties of four single crystals were measured.
Photoconductivity of the Ga5.5In4.5S15 in the range 400–760 nm were recorded.