▎ 摘　　要

The graphene/InP Schottky heterojunction solar cells, possessing a great significance in special applications of space optoelectronic devices, have been realized experimentally, however, the mechanism of the contact nature is lack. In this contribution, using first-principles calculation, we investigate the electronic properties and interface contacts of heterostructures through varying interlayer spacing and applying external electric fields. Our results indicate that graphene/InP is a typical vdW heterostructure with an equilibrium layer spacing of 3.65 angstrom. A small band gap of approximately 67 meV is opened, indicating a promising prospect concerning optoelectronic devices. Meanwhile, the formation of built-in electric field significantly promotes the separation of photogenerated electron-hole pairs. Additionally, the p-type Schottky contact with 0.04 eV p-type and 2.03 eV ntype SBH, respectively, is formed in the most stable configuration. Importantly, when the interlayer distance decreases below 3.6 angstrom, the heterostructure changes from p-type Schottky contact to p-type Ohmic contact. When exerting a negative electric field, the heterostructure belongs to p-type Ohmic contact. As the electric field increases to 0.55 V/angstrom, the transition from p-type to n-type Schottky contact is observed. These findings may be expected to have significant guiding value for design and fabrication of nano-devices based on graphene/InP vdW heterostructure.