Electron Transport in Borophene-Graphene Lateral Edge-Edge Junctions

Recently, a lateral heterojunction between borophene and graphene has been synthesized. This suggests borophene's potential application with graphene in nanoelectronics, and therefore, it is important to know the electron transport properties of their interface. We use density functional theory combined with the nonequilibrium Green's function method to calculate the transmission spectrum and the contact resistance of the junction at different doping levels. The electron transmission is determined by energy and momentum matching of borophene and graphene channels, as well as symmetry matching of wave functions. We find that the σ electrons in borophene are totally reflected at the interface, and π electrons have a transmission probability of up to 0.8. The high transmission probability leads to a low contact resistance of ∼115 Ω·μm at a doping p = 2 × 10¹² cm², better than state-of-the-art contacts from other metals such as Pd and Au, indicating borophene to be a good conductor in graphene-based devices.