Using first principles modeling, we predict how substitutional doping can influence the mechanical strength of a Ag/ZnO interface commonly found in various multilayer thin-film systems. Replacing Zn with a monovalent dopant strengthens the interface while dopants with a valence greater than two weaken it. Isovalent dopants have little effect. The results are explained in terms of charge transfer and hybridization effects at the interface. Although monovalent dopants are mechanically preferred, they do not inhibit Ag inter-diffusion in ZnO and could possibly cause chemical degradation of the interface. It is suggested that other dopants, such as Bi, avoid this issue by creating larger diffusion barriers while maintaining a relatively strong interface. The results indicate that complete control over the mechanics, kinetics, and chemistry of the interface requires a careful choice of dopant types and concentrations.
The band offsets at polar heterointerfaces that consist of group III-V zinc-blende semiconductors are investigated by first-principles modeling using the Heyd-Scuseria-Ernzerhof hybrid functional. Since the band alignment for such polar heterointerfaces and their constituent polar surfaces has not been fully elucidated and a reliable computational setup remains lacking, we propose in this paper the application of pseudo-H passivation in combination with the supercell approach adopting slab models. The pseudo-H passivation is shown to be a valid computational setup that quenches the macroscopic electric field generated by polar slab surfaces and stabilizes the electrostatic potential profile normal to the surfaces, and more consequentially, across the polar interface in the slab. This is essential to an accurate evaluation of the band offset at a polar interface using the supercell approach. The interfaces made of the polar (100) or ( 111) surfaces of AlP, AlAs, GaP, GaAs, InP, and InAs are studied. The predicted valence-band offsets are in good agreement with available experimental results. The offset values of most interfaces show weak dependence on their local chemical compositions, which is attributed to the formation of nearly complete interfacial chemical bonding.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.