STRUCTURE, STABILITY, AND ELECTRONIC-PROPERTIES OF PSEUDOMORPHIC (SI)(N) (GE)(M) SUPERLATTICES

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 con stant. Electronic properties are inferred from tight-binding calculati ons. 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.