The effects of reduced graphene oxide (rGO) on ZnO film UV-detector

摘要

In this work, pure and graphene incorporated ZnO thin films were prepared by sol-gel method on glass substrates and influence of graphene doping on the structural, electrical and optical properties of the films were studied. The results of Raman spectrum indicated the coexistence of ZnO and rGO in composite thin film. The FT-IR analysis of the composite sample showed that ZnO, ZnO-C heterojunction and C-C graphene skeletal peak are formed. The UV-Vis spectrum showed that both the transparency and band gap was partially decreased by graphene incorporation. The linear trend of I-V curve suggests an ohmic contact between ZnO and graphene nanosheets. In addition, the resistivity was decreased from 4.32×102 Ω·cm for pure ZnO film to 2.4×101 Ω·cm for composite film. The composite photodetector possessed a desirable signal to noise ratio and UV-sensitivity while the response time decreased to half of pure ZnO. The above results suggest that 0.225 wt.% rGO incorporation can improve the ultraviolet detection of ZnO thin film.