Interface spacing, stability, band offsets, and electronic properties on a (001) SrHfO3/GaAs interface: First-principles calculations

Abstract

SrHfO3 is a potential dielectric material for metal–oxide–semiconductor devices. The SrHfO3/GaAs interface has attracted attention because of its unique properties. In this paper, the interface properties of (001) SrHfO3/GaAs are investigated by first-principles calculations based on density functional theory. First, the adsorption behavior of Sr, Hf, and O atoms on the GaAs surface is investigated. An O atom has a lower adsorption energy on a Ga surface than on an As surface. Then, some possible (001) SrHfO3/GaAs configurations are considered to analyze the interface spacing, stability, band offsets, and charge transfer. The SrO/Ga(1) and HfO2/Ga(2) configurations are lower in binding energy than other interface configurations, indicating that they are more stable. Finally, we study the electronic properties of the SrO/Ga(1) and HfO2/Ga(2) configurations. The electronic density of states suggests that these systems exhibit metallic behavior. The band offset and charge transfer are related to the interface spacing. The valence band offset and charge transfer decrease with increasing interface spacing.