Visible-blind quasi-solid-state UV detector based on SnO2-TiO2 nanoheterostructure arrays

Self-powered UV detectors have attracted intensive research interest due to their advantages of low cost fabrication, high efficiency and low power consumption. In this paper, high ordered SnO2-TiO2 nanoheterostructure arrays were synthesized using soft chemical methods. A self-powered quasi-solid-state UV detector was constructed using this nanoheterostructure as the photoanode and a polyethylene oxide based quasi-solid-state electrolyte as the hole transfer layer. Because the SnO2-TiO2 core-shell nanoheterojunction simultaneously offers a high electron-hole separation, a low charge recombination and a direct pathway for electron transport, the nanostructured self-powered detector displayed an excellent performance over that based on bare TiO2 nanostructure arrays. A quite high incident photon-to-current conversion efficiency of 55.8% at 340 nm and a fast response time (0.14 s for rise time and 0.06 s for decay time) were observed. That is quite excellent performance for self-powered UV detector. Moreover, the self-powered UV photodetector also shows an excellent spectral selectivity and long-time stability in the air. These excellent photoelectric characteristics will enable significant advancements for next-generation photodetecting applications.