Flexible Self-Powered Real-Time Ultraviolet Photodetector by Coupling Triboelectric and Photoelectric Effects.

The portable UV photodetector is used to remind human timely from the overexposure to UV radiation. However, the traditional UV photodetector cannot meet the practical demands and power supply problem hinders its further development. In this work, we demonstrated a flexible, transparent and self-powered UV photodetector, by coupling of triboelectric effect and photoelectric effect. The device integrates a flexible ZnO nanoparticles (NPs) UV photodetector, a transparent and flexible film based TENG (TFF-TENG), commercial chip resisters and LEDs on flexible PET thin film. The TFF-TENG could harvest mechanical energy from finger tapping and sliding motion and power the ZnO NPs UV photodetector to realize self-powered detection. The voltage of the constant resistors connected with UV photodetector in series changes from 0.5 to 19 V under the UV light with power intensities increasing from 0.46 to 21.8 mW/cm2 and the voltage variation is reflected by the number of LEDs directly. The excellent flexibility and transparency of the device could extend its application scenarios; for example, such a portable device could be applied to real-time monitoring of the UV radiation to remind human from intense UV light.