Ternary compounds being formed in Cu(Ag) – Ga(In) – S(Se, Te) systems are promising semiconductors in optoelectronics. The technology of synthesis of these single crystals requires information on thermodynamic data. According to their state diagrams the Cu(Ag) – Ga(In) – S(Se, Te) systems are characterized by formation of ternary intermediate compounds.
The methods of electromotive force (e.m.f.) measurement and direct calorimetry have been used. The data on temperature and concentration dependence of e.m.f. allow us to establish correlation with state diagrams as well as to determine the partial and integral values of thermodynamic functions of ternary compounds formation.
On the basis of data obtained the atomization values have been calculated, which characterize the bond strength in crystals and are fit well with their melting temperatures, molecular masses and gap energies.
The results are presented in analytical form which provides information about thermodynamic properties of new unstudied semiconductor substances. The thermodynamic data have been used to obtain single crystals of ternary semiconductors by the method of chemical transport reaction.