Enhanced Ga2O3/SiC ultraviolet photodetector with graphene top electrodes

•β-Ga2O3/4HSiC based ultraviolet photodetectors are formed.•Enhanced UV photoresponse obtained using graphene electrodes.•Graphene offer a carrier transport channel for electron-holes separation.

Heterojunctions of β-Ga2O3/4HSiC are fabricated to form ultraviolet (UV) photodetectors by grown epitaxial β-Ga2O3 films on n-type 4HSiC substrates using laser molecular beam expitaxy technique. By replacing the top electrodes from Au/Ti to single-layer graphene, the devices show more obvious rectifying characteristics and enhanced UV photoresponse. The Ilight/Idark under 254 nm illumination increases from 4.81 to 63.31 and the responsivity increases from 7.14 × 10−4 A/W to 0.18 A/W. Our results suggest that the graphene transparent electrodes can not only allow the majority of the incident light to reach the contact area but also offer an easy carrier transport channel when the electron-holes were separated.