Flexible self-powered solar-blind UV photodetectors based on amorphous Ga2O3 modified carbon fiber cloth

Abstract

Self-powered solar-blind ultraviolet (UV) photodetectors are gaining increasing recognition as green, efficient, and sustainable devices, representing a development trend in the evolution of next-generation optoelectronics. Much efforts have been devoted to carbon-based materials for their excellent conductivity. Among these materials, commercial carbon fiber sheets stand out due to their distinctive 3D structure, impressive conductivity, cost-effectiveness, and flexibility, rendering them highly suitable for a wide range of photosensitive applications. The realm of flexible optoelectronic devices has garnered substantial interest owing to its pivotal role in diverse domains. However, the utilization of carbon cloth (CC) as a substrate for photodetectors remains an area ripe for exploration. This study aims to fabricate self-powered solar-blind UV photodetectors based on amorphous Ga2O3 (a-Ga2O3) thin films modified CC using a concise and efficient physical vapor deposition technique (magnetron sputtering). The results show that the optimal responsivity of the a-Ga2O3/CC photodetector is 16.98 mA/W, with response times of 0.16/0.10 s (rise/decay time). Even after 300 cycles of bending treatment, this self-powered photodetector maintains excellent cyclic stability and repeatability. Furthermore, first-principles calculation reveals a significant built-in electric field around the interface between a-Ga2O3 and CC, which can effectively separate photogenerated electrons and holes and suppress carriers’ recombination. This inherent mechanism allows the a-Ga2O3/CC-based photodetector to exhibit remarkable self-powered characteristics and prominent solar-blind detection ability.