Preparation of a flexible photoanode of the photoelectrochemical ultraviolet photodetector based on rutile TiO2 nanowires and the suppressed charge recombination at solid/liquid interface.

Flexible ultraviolet (UV) photodetector exhibits a promising application in portable electronic gadgets, display devices and biomedical imaging. In this study, a flexible photoanode of the photoelectrochemical (PEC)-type UV photodetector based on rutile TiO₂ nanowires (TiO₂ NWs) grown on carbon fiber cloth is realized. In photovoltaic applications, an insulating layer is usually introduced to suppress interfacial recombination and reduce the surface trap states. The interfacial recombination of semiconductor/electrolyte is suppressed by coating an Al₂O₃ barrier layer on the TiO₂ NWs. The photodetectors of the TiO₂@Al₂O₃ NWs show stable photocurrent, a high light/dark current ratio (I _light/ I _dark) of 1170, a faster rise and decay response times of 0.09 and 0.09 s, and excellent spectral selectivity from 300 to 400 nm. The peak responsivity of the photodetectors reaches 2.8 mA W⁻¹ at 360 nm. This flexible photoanode have a potential application in wearable PEC UV photodetector. [ABSTRACT FROM AUTHOR]