Optical and electrical properties of quarternary chalcogenides

Optical and electrical characterizations have been made on four compounds of the type Cu₂ZnA^IVX₄^VI with A^IV = Si, Ge and X^VI = S, Se. These compounds belong to either a tetragonal superstructure of zincblende (stannite) or to an orthorhombic superstructure of wurtzite (wurtz-stannite) where a_or = 2a_w, b_or = a_w/tr3, and c_or = c_w. The electrical and optical properties are found to parallel the size of the group IV or group VI atom present.