The study of thermal properties of solid solution crystals of type AIIIBIIIC2VI, which has become an object of extensive research, generally provides extensive information about the chemical and crystallographic structure of solid solution crystals, the nature of lattice defects in the crystal, and also the thermoelectric properties of binary solid solutions. Therefore, the study of the temperature dependence of the heat transfer coefficient is of special importance in order to obtain information about the transport of heat energy in AIIIBIIIC2VI type solid solution compounds.