Stability of impurity–vacancy pairs in germanium carbide

Abstract

Electronic structure simulation techniques have been used to study the binding energies of a range of substitutional impurity-vacancy pairs in germanium carbide and for comparison, in silicon carbide and in germanium. The calculations used a plane-wave basis set and pseudo-potentials within the generalized gradient approximation of density functional theory. Plane-wave pseudo-potential density functional theory has been used extensively to predict the defect behaviour in silicon, silicon germanium and germanium to aid experimental investigations. The calculations for germanium carbide indicate important differences in the binding energies of the impurity-vacancy pairs compared to silicon carbide and germanium.