Behavior of impurity copper in ZnGeP2 single crystals with diffusion doping

Results from a study of electrophysical and luminescent properties of zinc-germanium diphosphide single crystals, diffusion doped with copper, are presented. The nature of the dominant defects formed upon copper diffusion in ZnGeP2 is determined using a thermodynamic analysis of defect formation processes in ZnGeP2 and a ZnGeP2: Cu solid solution performed within the framework of the quasichemical analysis method. It is demonstrated that by choosing the copper diffusion method the hole concentration in the ZnGeP2 can be varied over the range 1012−1016 cm−3. A retrograde character was observed in copper solubility in ZnGeP2 compounds. Defect formation processes in ZnGeP2 upon copper diffusion depend on the degree of atomic ordering in the cation sublattice at the diffusion annealing temperature.