Interfacial interaction and effects of GaAs/Graphene hetero-structures studied by First-principle calculations

Abstract Developing new optoelectronic devices based on two-dimensional materials is an important research topic at present. In these developments, to construct GaAs/Graphene hetero-structure is becoming research hotspot, which can significantly improve the performance of GaAs-based optoelectronic devices. For the application of optoelectronic devices, the interfacial properties and effects are the key factors. However, these issues are not yet fully explored and understood so far, especially the atom diffusion from GaAs substrate to Graphene active layer. In the present work, the electronic structures and atom transportation of GaAs/Graphene hetero-structures were systematically investigated by First-principle calculations. The Ga or As atom, which diffuses from GaAs substrate to Graphene active layer, can open the zero-band-gap of Graphene. Furthermore, Ga atoms adsorbed onto Graphene is the most obvious to realize the purpose of opening the zero-band-gap of Graphene. Moreover, owing to the existence of interfacial built-in electric field, the electrons can efficiently transfer from GaAs substrate to Graphene active layer. This may be the underlying physical mechanism, by which to improve the optoelectronic performance of GaAs-based devices. The findings in this paper can explain the experimental phenomena reported in some literatures, and are helpful for the development of novel GaAs-based optoelectronic devices in the future.