Anion variations at semiconductor interfaces: ZnSe(100)/GaAs(100) superlattices

Abstract

Local interface composition and extended defect density in ZnSe/GaAs(001) and ZnSe/In 0.04 Ga 0.96 As (001) heterojunctions J.We extended our study of heterovalent interfaces between ZnSe͑100͒ and GaAs͑100͒ in superlattices using first-principles, density-functional theory calculations. Here, we concentrate on the changes in interfacial binding energy that occur when the stoichiometry is varied in the anion layer adjacent to the interface. This follows earlier work where the cation stoichiometry was varied. We studied three general categories of simple heterojunctions: those with only As-Zn bonding, those with only Se-Ga bonding, and those with mixed As-Zn and Se-Ga bonding. We also considered more complex interface configurations. Several different variations in interfacial stoichiometry that are conceptually based on the heteroepitaxial growth of ZnSe͑100͒ on the GaAs͑100͒͑2 ϫ 4͒␤2 surface structure were studied. In addition, the effects induced by the presence of vacancies in the vicinity of the surface were investigated. These more complex interfaces are discussed in terms of published experimental results. Finally, the possibility that the energy of the interface can be described in terms of the energy of the bonds that span that interface was also examined. We find that, for all of the 14 interfaces studied, the interface energy can be expressed as a simple sum of the per-bond-pair energies with an average error of less than 3%. Therefore, in these systems, the energies of the interfacial bonds are "additive" to a good approximation.

Chemical trends of stability and band alignment of lattice-matched II-VI/III-V semiconductor interfaces

“…In the structures A, B, C and D, the mixed interfaces are formed either by one Ga atom plus one Zn atom or by one Sb atom plus one Te atom. In another word, the stable mixed interfaces are constructed by 50% Sb and 50% Te atoms or by 50% Ga and 50% Zn atoms, as predicted by previous studies [19][20][21] , and there are two Ga-Te and two Zn-Sb "wrong bonds" at the interfaces. As we know, the Zn-Sb bond is an acceptor bond, providing 1/4 holes, and Ge-Te bond is a donor bond, providing 1/4 electrons.…”

Structural Studies of the Epitaxial Layer of a Substitutional Solid Solution (GaAs)1−x(ZnSe)x with Nanocrystals

“…Funato et al had investigated MOVPE growth procedures of GaAs/ZnSe heterostructures, the ZnSe-GaAs heterovalent quantum structures were fabricated, and their optical properties were characterized [3]. Farrell and LaViolette studied [4] three categories of simple heterojunctions that have links: (1) only As-Zn, (2) only Se-Ga, and (3) mixed As-Zn and Se-Ga bonds and more complex interface configurations, as well as various versions of interfacial stoichiometry [5]. He showed that the energy of the interface can be expressed as a simple sum of the energies of pairs with one bond, with an average error of less than 3%.…”