Enhanced UV-light detection based on ZnO nanowires/graphene oxide hybrid using cost-effective low temperature hydrothermal process

A new low-cost optimized hydrothermal process of direct synthesis of ZnO nanowires (NWs)/graphene oxide (GO) hybrid on silicon substrates at a low growth temperature (∼60°C) is reported. The careful optimization of the growth conditions and ZnO/GO relative ratios have resulted in high-density ZnO NWs formation with homogenous density and size distributions directly on GO sheets. The fabricated nanocomposites were intensively investigated by employing different structural, optical and electrical characterization techniques such as SEM, EDX, XRD, FTIR, UV-VIS and I-V. SEM analysis showed a formation of highly dense ZnO NWs on GO sheets with homogenous size distributions with average approximate diameter and length of 70 nm and 310 nm, respectively. The EDX combined with FTIR and XRD measurements confirmed the exact chemical composition of the intended structure. The room-temperature UV-VIS spectra revealed an enhance optical absorption of UV-light at an absorption band centered at 370 nm. Under UV-excitation a significant photocurrent increase has been observed. This is can be attributed to the large surface to volume ratio in ZnO-NWs structure, which is associated with oxygen desorption at the large ZnO-NWs surfaces that reduces the recombination rate of photogenerated free charge carriers. The optimum electrical and optical properties of the device have been observed at ZnO-NWs/Go relative ratio of 1:5. These findings could be promising for potential enhanced UV-detectors and flexible optoelectronics devices.