Effect of graphene film thickness on photoluminescence properties of ZnO/graphene composite films

As an excellent reinforcing material, graphene is widely utilized to composite with various functional materials, such as ZnO with hexagonal wurtzite structure. Due to their high lattice fitting degree, numerous properties of ZnO material are reinforced, such as conductivity and photoluminescence (PL) characteristics, etc. However, the mechanism of the influence of graphene film thickness on PL in composite films remains to be explored. Moreover, it remains to be explored how thick graphene film is more suitable for composite with ZnO film to achieve the best PL performance enhancement effect. The motivations of this study are based on the above two points, under the constant optimal ZnO sputtering process, the ZnO film was compounded with five kinds of graphene films with different thickness, and the surface morphology and growth quality of the grown ZnO films were analyzed in detail, to obtain the effect mechanism of the variation of graphene film thickness on the growth quality of ZnO; and to explore the optimal preparation parameters, dimension parameters, and the crystalline information of the graphene film, which can be most appropriately composite with ZnO film to make the strongest ultraviolet PL properties.