Electrical and Optical Properties of the CuGa(S1-xSex)2 System

Abstract
The mixed crystal system CuGa(S1-x Se x )2 was prepared by the normal freezing method. The compositional dependence of the lattice constants and the optical band gap obeyed Vergard's law. The phase diagram of this system was studied by DTA measurement. An orange photoluminescence was observed for x≦0.5 after annealing in vacuum. It was confirmed that the emission was due to D-A pair recombinations, and an increase of S-vacancy caused an increase of photoluminescence intensity. The electrical resistivity was also affected by S-vacancy.