Electronic structure and optical properties of B-, N-, and BN-doped black phosphorene using the first-principles

The structural stability, electronic structure, and optical properties of BN-doped black phosphorene systems at different concentrations were investigated using a density generalized theory approach based on the first principles. BN-doped black phosphorene was found to be more stable than B and N atom doping. With the increase of doping concentration, the stability of the structure gradually decreases, and the structure of the system with 25% doping concentration is the most stable. The intrinsic and N-doped black phosphorenes are direct bandgap semiconductors, and B and BN doping make the black phosphorene change from direct bandgap to the indirect bandgap. The total density of states is mainly contributed by the p-state electrons of the B and P atoms, and the N atoms have a role in the local density of states with little contribution to the overall one. The black phosphorene undergoes charge transfer between the B and N atoms. The amount of charge transfer increases with the increase of doping concentration. The BN-doped black phosphorene system is blue-shifted at the absorption and reflection peaks compared to the intrinsic black phosphorene system. From the dielectric constant, it is found that the doped system is shifted towards higher energy at the highest peak, leading to an increase in the intensity of the electric field generated by light, which is beneficial to increase the efficiency of photovoltaic power generation. The photoconductivity decreases and shifts toward higher energy after doping, with the most pronounced performance at BN doping concentrations of 12.5% and 25%.