Cation variations at semiconductor interfaces: ZnSe(001)/GaAs(001) superlattices

Abstract

of in-plane strain anisotropy in ZnSe(001)/GaAs layers using reflectance difference spectroscopy J.We investigated the possibility that the interface energy in heteroepitaxial compound semiconductor systems can be characterized by a unique value. We suggest that the per-bond binding energy, which is associated with the strength of the chemical bonds that span the interface between the different compounds, is this desired value. We chose the ZnSe͑001͒/GaAs͑001͒ system for this study because of its relatively small lattice mismatch. Three chemically different interfaces were studied: One containing only Ga-Se bonds, one containing only Zn-As bonds, and one with an equal ͓i.e., 50:50͔ mixture of these bonds. We employed first-principles density-functional theory electronic-structure calculations to obtain the structure and binding energy of the bonds and these interfaces, for a variety of unit cells in order to find the favored configurations under static lattice conditions. The destabilizing effect of an interfacial charge imbalance, and, one of the limitations of density-functional theory calculations in this circumstance are also discussed.

ZnSe∕GaAs(001)heterostructures with defected interfaces: Structural, thermodynamic, and electronic properties

“…As mentioned before, the 1V-swap configuration is unstable with respect to 1V, in the whole range of chemical potentials. This result is consistent with the experimental indication of Ga-Se bonds but no Zn-As bonds and with the results of Ref 35. which is however limited to undefected interfaces and does not take into account the charge neutrality prescription.…”

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.…”

Effect of ZnSe/GaAs interface treatment in ZnSe quality control for optoelectronic device applications

“…Zn and Se pre-treatment of the GaAs surface were shown to influence the band-offsets and defect densities in ZnSe epilayers grown on GaAs substrates [2,3]. However, conflicting conclusions about the effectiveness of these pretreatments are prevalent in the literature, making it difficult to determine which treatments are most optimal for high quality interface formation [4]. Many of these conclusions were drawn from measurements performed on the ZnSe epilayers.…”

“…The role of As coverage on the GaAs surface and the use of Zn or Se pre-treatment prior to ZnSe layer growth were examined. Low-temperature photoluminescence (LT-PL), X-ray 4 photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and high-resolution X-ray diffraction (HRXRD) were used to correlate interface stoichiometry with the resulting ZnSe/GaAs interface, as well as ZnSe and GaAs properties. We find that starting with an Asterminated surface is necessary to minimize secondary phase and defect formation at the ZnSe/GaAs interface by moderating Ga-Se bonding.…”