Stable interface structures of heterovalent semiconductor superlattices: The case of (GaSb)n(ZnTe)n

Abstract

Using first-principles total energy calculation and Monte Carlo simulation, as well as lattice harmonic expansion, we have revealed the chemical trends of the stable atomic configurations at the interface of lattice-matched heterovalent superlattices. Using (GaSb)n(ZnTe)n superlattices as an example, we find that the interfacial energy depends not only on the bond energy but also on the Coulomb energy derived from the donor and acceptor wrong bonds. At short-period limit (n=1), the abrupt [111] interface has the lowest energy even though it is polar, whereas for the long-period superlattices, the nonpolar [110] interface has the lowest energy. This finding provides a general guidance on growing stable lattice-matched heterovalent superlattices for optoelectronic device applications.