Improving Optoelectrical Properties of Ga₂O₃ Photodetector by Reduced Graphene Oxide (rGO) Decoration for Deep UV Photodetection

Deep ultraviolet (200-280 nm) photodetectors have received much attention in the fields of biology, industry, military, etc. The promising optical and electrical properties of wide bandgap, n-type gallium oxide (Ga₂O₃) make it quite suitable for deep UV photodetection. Our work shows that decorating reduced graphene oxide (rGO) can further enhance the photoresponse of the Ga₂O₃ photodetector (PD). rGO - a 2D material has received a lot of interest recently because of its distinctive qualities. In this work, we fabricated rGO/Ga₂O₃ heterostructure for deep UV photodetection where Ga₂O₃ thin film was deposited on c-plane sapphire substrate using Pulsed laser deposition, and rGO was synthesised by modified hummers method followed by thermal reduction, which was then drop casted on Ga₂O₃ film. The photoresponse of the rGO/Ga₂O₃ PD illuminated under 250 nm light was found to be substantially higher than the Ga₂O₃ PD, indicating an improvement of photoelectric properties for the UV photodetector based on Ga₂O₃ thin film. The dark current was found to be lower for rGO/Ga₂O₃ PD, and the illumination-to-dark current ratio (I_illumination/I_dark) was increased to 78.31 from 7.30 for Ga₂O₃ PD at a voltage of 5 bias and power density of 12.83 mW/cm². Thus, it can be concluded from the results that rGO/Ga₂O₃ PDs have great promise for photodetection applications.