Theoretical investigation the growth of Fe3Si on GaAs: Stability and electronic properties of Fe3Si/GaAs(0 0 1), (1 1 0) via DFT

Abstract

In this paper, we study the difference in stability between two low refractive index interfaces (0 0 1) and (1 1 0) of Fe3Si/GaAs heterostructures, the optimal geometry, adhesion work, interfacial energy, interfacial distance and interface electronic structure were calculated by using density functional theory (DFT). We constructed four different Fe3Si/GaAs heterostructures models by combining different stacking methods with two interfaces. Changes in interfaces and stacking methods can affect adhesion work, interfacial distance, and interfacial energy. The research shows that the hollow-site has a larger adhesion work and smaller interfacial energy than the top-site. Based on the data of the adhesion work and the interfacial energy, the mechanical properties and ductility of the (0 0 1) interface with hollow-site is stronger than others. In order to enhance the stability and fracture toughness of the system, more (0 0 1) interface with hollow-site need to be formed. At the same time, it has the smallest interfacial energy and is easier to form. The electronic structure of the (0 0 1) interface with hollow-site and the contribution of electron orbital hybridization to the formation of covalent bonds at the interface are also discussed. A new covalent bond is formed at the interface, and Fe-As bond is easier to form than Si-As bond.