Cd(OH)2@ZnO nanowires thin-film transistor and UV photodetector with a floating ionic gate tuned by a triboelectric nanogenerator

Abstract The adsorbed ions on the surface of nanowires thin-film, such as O2−, are acted as a floating gate, modulating significantly the thin-film's electronic and optoelectronic properties. However, due to the lack of tuning means for surface ions, the floating ionic gate has not been applied in developing electronic and optoelectronic nanodevices. Here, based on the gas discharge induced by a triboelectric nanogenerator (TENG), the tuning of surface ions on Cd(OH)2@ZnO nanowires thin-film is achieved, and the thin-film transistor (TFT) and thin-film photodetector (TFP) have been fabricated by using the surface ions as a floating ionic gate. In the TFT with a floating ionic gate, the current can be tuned step-by-step as the operation cycles of TENG is controlled, and the maximum on-off ratio of current reaches 4.0 × 105. In the UV light TFP with a floating ionic gate, the on-off ratio and recovery time constant of photocurrent reach 2.7 × 107 and 0.53 s, achieving a simultaneous enhancement of sensitivity and recovery speed by a factor of 1350 and 946 times, respectively. O2− is identified as the surface ions on the nanowire thin-film, and the tuning mechanism has been discussed. Because of the low cost and easy operation of the TENG, the floating ionic gate technology based on TENG provides a promising strategy for developing novel electronic and optoelectronic nanodevices with enhanced performances by constructing a device system.