Structural, electronic and optical properties of graphene/C2P4 van der Waals heterostructures with direct bandgap and high absorption coefficient

In this paper, we formed two graphene/C 2 P 4 van der Waals (vdW) heterostructures (HSs) by stacking the graphene and the C 2 P 4 monolayer which have been predicted by us. First, we investigated the stability of C 2 P 4 monolayer, and calculated the binding energies and flat average differential charge density of two vdW-HSs. Second, we found that two graphene/C 2 P 4 vdW-HSs are all direct semiconductors with bandgap as 0.051/0.064[Formula: see text]eV and 0.536/0.697[Formula: see text]eV under GGA-PBE/HSE06 functional, respectively, which provides a way to unfold the zero bandgap of graphene or let an indirect monolayer to be a relevant direct semiconductor. Additionally, two graphene/C 2 P 4 vdW-HSs possess high absorption coefficients (16%∼18%) for the visible light and higher absorption coefficients (22%) for the near ultraviolet light, respectively. These admirable properties make two vdW-HSs as novel and potential two-dimensional materials applied on optoelectronic, electronic and photovoltaics devices.