Graphene quantum dots/ZnO nanowires composites for efficient ultraviolet sensing

The photocurrent of traditional ZnO ultraviolet detector is low. Due to the high carrier mobility of graphene, the idea of employing Graphene Quantum Dots as photosensitizers of electron transporting medium was proposed. The phenomenal performance of ZnO-GQD composites was attributed to the efficient immobilization of GQDs on ZnO nanowires via an inexpensive spin-coating method. A simple spinning annealing method was used to make graphene QDS compound on the surface of ZnO nanowires. After the surface of ZnO nanowires being modified by graphene quantum dots, the photocurrent of the ZnO photodetector was increased from 9.5 μA to 65 μA under the condition of 5 V bias voltage and UV irradiation with wavelength of 365 nm and power of 1.35 mW /cm². The photocurrent was increased by 6.8 times. This simple spinning annealing method reduces the processing technology of UV photodetector and improves the performance of the photodetector, which will provide a beneficial reference for the next generation of sustainable green development strategy and the design of high efficiency and low cost photoelectric equipment.