Enhanced UV photoresponse employing 3D graphene nanowalls/SnO2 nanocomposite film

Ultraviolet (UV) photodetectors based on wide bandgap semiconductors have been widely used in industrial and scientific applications. However, the weak photoresponse due to the rapid recombination of photogenerated electron-hole pairs greatly limits their practical applications. Here, we proposed a kind of high-performance UV photodetectors combining the wide bandgap semiconductor SnO2 with three-dimensional (3D) graphene nanowalls (GNWs). The as-prepared GNWs/SnO2 nanocomposite film show strong absorption in the wide UV region, which can be used as the photosensitive material for UV detection. Benefiting from the 3D GNWs networks with excellent electrical conductivity, the recombination of the photo-induced electron-hole pairs can be effectively suppressed. This results in great enhancement for photoresponse of GNWs/SnO2 nanocomposite film compared with that of the pure SnO2. With optimized GNWs content of 0.05 wt%, the devices exhibit clear photoresponse with photocurrent density of 276 mu A/cm(2) at bias voltage of 1 V. Meanwhile, the devices exhibit excellent reproducibility and high long-term stability for one-month storage in air. Our study provides a promising strategy for developing high-performance UV photodetectors with eco-friendly, excellent stability and low cost.