Directional dependence of the electronic and transport properties of 2D borophene and borophane

Very recently two dimensional layers of boron atoms, so called borophene, have been successfully synthesized. It presents a metallic band structure, with a strong anisotropic character. Upon further hydrogen adsorption a new material is obtained, borophane; giving rise to a Dirac cone structure like the one in graphene. We have performed a first-principles study of the electronic and transport properties of borophene and borophane through the Landauer–Buttiker formalism. We find that borophene presents an electronic current two orders of magnitude larger than borophane. In addition we verified the direction dependence of the electronic current in two perpendicular directions, namely, Ix and Iy; where for both systems, we found a current ratio, η = Ix/Iy, of around 2. Aiming to control such a current anisotropy, η, we performed a study of its dependence with respect to an external strain. Where, by stretching the borophane sheet, η increases by 11% for a bias voltage of 50 mV.