Tuning the electronic and optical properties of phosphorene by transition-metal and nonmetallic atom co-doping

The electronic and optical properties of phosphorene co-doped with vanadium and nonmetallic atoms (B, C, N and O) are investigated by employing first-principles calculations based on density functional theory. It is found that the geometrical, electronic and optical properties are affected distinctly by these dopants. Significant local lattice distortions are observed in all of the V-X (X = B, C, N or O) co-doped systems. All the substituted systems retain their semiconducting character, but their band gaps become smaller than that of primitive phosphorene. This indicates that impurity doping is an effective way to modulate the band gap of phosphorene for different applications in electronic devices. Obvious covalent interactions exist between the impurities and their adjacent phosphorus atoms. In these doped systems, an interesting redshift phenomenon and significant anisotropy are observed in their optical properties. Our theoretical investigations suggest an alternative method towards modulating the electronic and optical properties of phosphorene, and predict potential applications of phosphorene in nanoelectronic and optical devices.