Quadrupole Interaction in Ternary Chalcopyrite Semiconductors: Experiments and Theory

Abstract

Electric field gradients have been measured at substitutional lattice sites in ternary semiconductors using Perturbed γ -γ Angular Correlation spectroscopy (PAC). The experimental results for AIBIIIC2 chalcopyrite structure compounds and • AIIB2IIIC4IV defect chalcopyrites are compared with ab nitio calculations. The latter were carried out with the WIEN code that uses the Full Potential Linearized Augmented Plane Wave method within a density functional theory. The agreement between experiment and theory is in most cases very good. Furthermore, the anion displacements in AgGaX2 -compounds (X: S, Se, Te) have been determined theoretically by determining the minimum of the total energy of the electrons in an elementary cell.