Optoelectronic Properties of Borophene, a Two-dimensional Transparent Metal, from Many-body Perturbation Theory

Borophene is a recently synthesized metallic sheet that displays many similarities to graphene and has been predicted to be complimentary to graphene as a high density of states, optically transparent 2D conductor. We present a first-principles density functional theory and many-body perturbation theory study aimed at understanding the strain-dependent optoelectronic properties of two likely allotropes of borophene that are consistent with experimental scanning tunneling microscopy images. We predict that both structures behave as transparent conductors, with conductivity that is smaller than graphene and limited by electron-phonon scattering. Additionally, we demonstrate that strains consistent with change in substrate can be utilized to modify the optoelectronic properties of borophene, suggesting that modification of growth conditions can be used to tune these properties.