Building efficient photoelectric properties with Si/Graphene/ZnO interface structure

Abstract

We perform a numerical evaluation and test characterization on adjusting the bonding of the Si/ZnO interface to improve the photoelectric properties of the Si/ZnO heterojunction. We used Graphene as a buffer layer to perform density functional calculations to investigate the interfacial characteristic and photoelectric characteristic of Si/ZnO and Si/Graphene/ZnO. The results show that the Si–O covalent bond is formed in Si/ZnO interlamination; the Si/Graphene/ZnO interlamination's interaction is Van der Waals force. We detected some interesting phenomena that due to the insertion of Graphene, the valence band of the Si/Graphene/ZnO structure moves to the conduction band, the conductivity of the system is improved, the dominant proportion of Si/Graphene/ZnO in visible light utilization is 74.50 % higher than that of Si/ZnO. It implies a detailed understanding for manipulating the photoelectric properties with Si/Graphene/ZnO structure for getting high effecint photoelectric conversion in solar cell applications. The presence of O atoms at the layer interface also affects the conductivity of heterojunctions. It is proved experimentally that the introduction of Graphene makes ZnO grow better on Si substrate, and improves the photoelectric performance of heterostructures.