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

Abstract In the present study, by adding graphene to a photoconductive photodetector with a niobium pentoxide (Nb 2 O 5 ) absorber layer and exploiting the photogating effect, the responsivity of the photodetector is significantly improved. In this photodetector, the Nb 2 O 5 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 Nb 2 O 5 photogating photodetector are compared with those of the corresponding photoconductive photodetector. Also, the Nb 2 O 5 photoconductive and photogating photodetectors are compared with titanium dioxide (TiO 2 ) photoconductive and photogating photodetectors in terms of responsivity at different applied (drain-source) voltages and gate voltages. The results show that the Nb 2 O 5 photodetectors have better figures of merit (FOMs) in comparison with the TiO 2 ones.