The controllable electronic characteristics and Schottky barrier of graphene/GaP heterostructure via interlayer coupling and in-plane strain

• The graphene/GaP heterostructure is dominated by vdW interaction. • The equilibrium interlayer spacing is 3.40 Å and the binding energy is −39.35 meV. • A tiny bandgap of 20 meV has opened at the Dirac point. • The interlayer distance and biaxial strain may change the contact mode. • A conversion from p-type Schottky to p-type Ohmic contact is present. Establishing the desired heterostructures by assembling suitable semiconductor materials has shown significant potential for applications in next-generation micro-nano electronic devices. In this present contribution, we demonstrate the geometric structure and electronic properties of graphene/GaP heterostructure by first-principles calculations. It is found that the heterostructure is characterized by weak interlayer coupling accompanying the stable layer spacing of 3.40 Å and binding energy of −39.35 meV, meaning that the interlayer is dominated by van der Waals (vdW) force. The electronic band structure of free-standing graphene and GaP monolayers are preserved well. Meanwhile, a tiny bandgap of approximatively 20 meV at the Dirac point of graphene is opened, which is attributed to the breakdown of sublattice symmetry. In the ground state, the Schottky contact of p -type is present with the n -type and p -type SBH of 1.71 eV and 0.10 eV, respectively, which can be effectively induced by imposing interlayer coupling as well as in-plane strains. Especially, the transition of p -Schottky contact to p -Ohmic contact occurs when the layer spacing decreases to 3.20 Å or the strain increases to +2 %. These theoretical results may offer potential guiding principle in future electronic devices.