Experimental comparison between Nb₂O₅- and TiO₂-based photoconductive and photogating GFET UV detector

In the present study, by adding graphene to a photoconductive photodetector with a niobium pentoxide (Nb₂O₅) absorber layer and exploiting the photogating effect, the responsivity of the photodetector is significantly improved. In this photodetector, the Nb₂O₅ layer detects the light, and the graphene improves the responsivity based on the photogating effect. The photocurrent and the percentage ratio of the photocurrent to dark current of the Nb₂O₅ photogating photodetector are compared with those of the corresponding photoconductive photodetector. Also, the Nb₂O₅ photoconductive and photogating photodetectors are compared with titanium dioxide (TiO₂) photoconductive and photogating photodetectors in terms of responsivity at different applied (drain-source) voltages and gate voltages. The results show that the Nb₂O₅ photodetectors have better figures of merit (FOMs) in comparison with the TiO₂ ones.