High-Efficiency Photoelectric Detector Based on a p - n Homojunction of Monolayer Black Phosphorus

We numerically investigate the high-efficiency photovoltaic effect in a lateral p-n homojunction based on monolayer black phosphorus (MBP) by using the nonequilibrium Green's function combined with the density-functional theory. Because of the built-in electric field of the p-n junction and the wrinkle structure of MBP, the photocurrent excited by either linearly or elliptically polarized light is significantly enhanced in a wide photon energy range. Moreover, because of the electron-photon interaction, the photocurrent is related to atomic orbitals through the polarizing angle of the polarized light. Therefore, we can read the orbital information of the band structure from the polarizing angular distribution of the photocurrent. These findings suggest the promising application of the MBP-based p-n homojunction in high-efficiency photoelectric devices and orbital-resolved photovoltaic detection.