Regulating the electronic and optic properties of hexagonal boron nitride nanosheets via phosphorus doping

The application of hexagonal boron nitride nanosheets (h-BNNSs) in electronical and optical fields is limited due to their wide band gap. In this letter, we report a first-principles study on the electronic and optic properties of phosphorus (P) functionalized h-BNNSs. The results show that the introduction of P atoms leads to a valid modification of h-BNNS band structure which can reduce the width of band gap from 4.643 eV to 0.824 eV. The transformation from insulator to semiconductor of h-BNNSs is achieved through this band width regulation, and all P-doped h-BNNSs exhibit an active response to the visible light. In particular, with the increase in the number of doped P atoms, the absorption wavelength range can cover the whole visible region. In terms of the analysis of electronic structures and absorption spectra of the P-doped h-BNNSs, an enhancement mechanism of the visible-light response for the effect of the introduction of P atoms is proposed. It is expected that P-doped h-BNNSs could be used as potential metal-free efficient visible-light-driven photocatalysts.