Synergistic effects of Schottky Interface and persistent photo-trapped charges in perovskite for light-enhanced triboelectric nanogenerators

With the advancement of next-generation technologies, such as the Internet of Things (IoT) and wearable electronics, the demand for self-powered energy sources is rapidly increasing. In response, triboelectric nanogenerators (TENGs) have attracted significant attention as promising candidates for energy harvesting and self-powered sensing. However, their limited output performance and restriction to single mechanical stimuli have impeded their practical utilization as multifunctional sensors. To overcome these constraints, hybrid nanogenerators integrating multiple energy conversion mechanisms have been actively developed. Among these, photo-triboelectric hybrid nanogenerators, incorporate photoresponsive materials, enable the simultaneous harvesting of light and mechanical energy, offering potential for self-powered optical sensing. Despite this progress, the quantitative understanding of electrical output variation and the underlying mechanisms under light illumination remains a significant challenge. In this work, a light-enhanced triboelectric nanogenerator (LE-TENG) is designed using the photoresponsive semiconductor methylammonium lead iodide (MAPbI₃) as the triboelectric layer, and the mechanisms responsible for light-induced output enhancement involving both triboelectric and tribovoltaic effects are quantitatively investigated. Surface potential measurements reveal that illumination induces a shift in the MAPbI₃ surface potential from −588 mV to −772 mV, accompanied by persistent trapping of photoexcited electrons. This modulation of surface potential directly contributes to enhanced triboelectric output. Furthermore, a Schottky junction formed at the Cu/MAPbI₃ interface establishes a built-in potential that efficiently separates photoexcited carriers, thereby increasing the tribovoltaic output. These findings provide a quantitative understanding of charge separation and interfacial potential modulation, offering a theoretical foundation for designing high-performance photoresponsive hybrid TENGs for next-generation IoT and wearable applications.