ZnO/Gra/Si structure to improve photoelectric properties

To enhance the interface bonding and optoelectronic properties of ZnO/Si, we employed graphene (Gra) as a buffer layer to mitigate lattice mismatch. Density functional theory (DFT) was utilized to analyze the impact of graphene insertion on the interface structure and optoelectronic properties of ZnO/Si. Our findings indicate strong covalent bonds within the ZnO/Si interface, whereas the ZnO/Gra/Si interface exhibits van der Waals interactions. Additionally, the incorporation of graphene shifts the valence band of ZnO/Gra/Si closer to the conduction band, significantly improving its conductivity. Moreover, ZnO/Gra/Si demonstrates a 74 % increase in visible light utilization compared to ZnO/Si, highlighting the substantial potential of this sandwich structure in solar cell applications.