Low temperature in-situ preparation of reduced graphene oxide/ZnO nanocomposites for highly sensitive photodetectors

Unlike traditional approach to improve photoresponse performance of ZnO-based optoelectronic devices, a ultra-low temperature solvothermal process was utilized to prepare reduced graphene oxide (rGO)/ZnO nanocomposites, which realized non-surfactant in-situ preparation of rGO/ZnO nanocomposites with the reduction of graphene oxide (GO) at the low temperature process (<170 °C). The effect of annealing process on the microsturcture and photoelectronic properties of rGO/ZnO nanocomposites and pure ZnO was investigated. The diameter of as-synthesized ZnO nanocrystal in GO/ZnO precursor was about 6.5 nm. The Fourier transform infrared (FTIR) and Raman spectrum results showed that graphene oxide in the precursor has been reduced to rGO. When annealing at a mild temperature below 170 °C, the optimum photocurrent of rGO/ZnO nanocomposites was about 4.5 times compared to pure ZnO, and the corresponding detectivity reached 6.39 × 1010 Jones. The advantage of the low temperature in-situ technic provides an avenue to fabricate high-performance and low-cost optoelectronic devices.