Photoelectric properties of 2D ZnO, graphene, silicene materials and their heterostructures

We investigated the photoelectric properties of Graphene (Gra)/ZnO, Gra/Silicene (Si) and ZnO/Gra/Si heterostructures by using density functional calculations. The results show that ZnO, Gra and Si retain their respective electronic properties, which results from the van der Waals (vdW) interlayer interaction between the heterogeneous interfaces. We also can find that the band gap of ZnO: ZnO (1.67 eV) < Gra/ZnO (1.74 eV) < ZnO/Gra/Si (1.76 eV). ZnO/Gra/Si with sandwich structure has the best photoelectric performance.