Stability and electro-optical properties of hydrogen-functionalized monolayer BC3H3: A theoretical study

Abstract

Utilizing the PBE+G0W0+BSE calculations from density-functional and many-body perturbation theories, we systematically investigate the stability and electro-optical properties of hydrogen-functionalized monolayer BC3H3 across four configurations. BC3H3 monolayers with type-3 & 4 configurations are verified to be stable dynamically and thermally. The type-3/type-4 is predicted to be a direct/indirect semiconductor with a moderate quasi-particle bandgap. Applied biaxial strain and external electric field both can effectively tailor the bandgap over a broad range, even induce a semiconductor-metal phase transition in both configurations. In particular, a biaxial tensile strain of +1.1% and vertical electric field of ~ ± 0.05V/Å can cause an indirect-to-direct gap transition in the type-4. Moreover, the type-3 and type-4 configurations also show significant absorption coefficients for the near-ultraviolet light (larger than 105 cm-1) and large exciton binding energies. These results will be important for designing the ultraviolet photoelectric devices based on BC3H3 monolayer.