Experimental comparison between photoconductive and graphene-based photogating detection in a UV-A region

Photoconductive detectors that use intrinsic absorbent materials include a wide range of detectors. In this paper, a photoconductive detector is fabricated using a titanium dioxide (TiO2) thin film. The mechanism of the photo -detector is changed to the photogating mechanism by transferring monolayer graphene onto the TiO2 thin film, which shows a great responsivity with a slight change in the fabrication process. Since the maximum responsivity can be obtained by applying and adjusting the gate voltage, the gate voltage is set in all experiments, and the effect of the gate voltage is investigated in both detectors. It is observed that by increasing the gate voltage, the responsivity of the photogating detector increases to 40 A/W at a gate voltage of 15 V. However, in the photoconductive detector, the increase in the gate voltage does not have a particular effect on the detector responsivity. In the photogating detector, the increase in the responsivity due to the increase in the gate voltage is attributed to applying the gate volt-age to the graphene layer and not the absorber layer. The efficiency of both detectors is confirmed up to a frequency of 5 kHz.& COPY; 2023 Optica Publishing Group

Automated summary

A photoconductive detector using a titanium dioxide (TiO2) thin film is fabricated in this paper, and the mechanism is changed to photogating by transferring monolayer graphene onto the film. The responsivity of the photogating detector can be increased to 40 A/W at a gate voltage of 15 V, while the gate voltage has no significant effect on the responsivity of the photoconductive detector. The increase in responsivity in the photogating detector is attributed to the application of gate voltage to the graphene layer. The efficiency of both detectors is confirmed up to a frequency of 5 kHz.