Investigation of ambient regulated enhanced photo-responsive properties of GO-ZnO and transition metal doped GO-ZnO nanocomposite: Improved photocurrent and swift response

Abstract

In this work, UV photodetector was fabricated by synthesising zinc oxide (ZnO) on fluorine doped tin oxide (FTO) thin film via a one-pot synthesis method. The incorporation of GO into the ZnO growth solution resulted in an increase of UV photocurrent of the ZnO UV detector by up to 300%, while cooper doping of the GO-ZnO nanocomposite enhanced the response time by 22%. The photo-responsive property is enhanced by including graphene oxide (GO) (0.1%–10%) in the ZnO growth solution. The increased growth of nano-flake like ZnO nanostructure is confirmed from FE-SEM images. 0.5% GO-ZnO nanocomposite devices have shown a photocurrent of 610.4 μA. The FTO-0.5% GO-ZnO device also had a responsivity of 4.92 AW-1, an EQE of 1696.48%, and a specific detectivity of 7.3 × 1011 Jones. The devices were tested under varied working temperatures and relative humidity levels to ensure their utility and effectiveness. The FTO/GO-ZnO:Cu device showed a response and recovery times of 62.47 s and 174.22 s, respectively, 22% faster than the other reported devices.