Structure, stability, and electronic properties of pseudomorphic (si)n/(ge)m superlattices

Abstract

We investigate the structure, energetics, and electronic properties of (Si)5/(Ge)5 and (Si)3/(Ge)4 superlattices. Our analysis, based on the empirical-potential approach, shows that the thermodynamic stability of these superlattices decreases with increasing substrate lattice constant. Electronic properties are inferred from tight-binding calculations. Use of the interatomic distances obtained here and of those given by elastic theory leads to similar results for the band structure and transition probabilities.