Rolling‐Mode Tribovoltaic Nanogenerator Based on Lead‐Free Perovskite With Nonlinear Photo‐Enhanced Performance via Dual‐Electric‐Field

ABSTRACT Tribovoltaic nanogenerator (TVNG), as an emerging energy harvesting technology, is capable of converting environmental mechanical energy into direct‐current electrical energy, thus attracting widespread attention. However, most of the perovskites prepared for TVNG are lead‐containing, and the mechanism of the photo‐enhanced output performance of TVNG is also unclear. Herein, the all‐inorganic lead‐free perovskite CsBi ₃ I ₁₀ was introduced and a rolling‐mode TVNG based on a Cu/CsBi ₃ I ₁₀ dynamic Schottky junction was constructed. Under AM 1.5 G illumination, the open‐circuit voltage and short‐circuit current of the TVNG reach 0.46 V and 15.5 µA, respectively, representing increases of 230% and 250% compared to those in the dark state. Moreover, a nonlinear photo‐enhancement effect was observed, that is, the output signal of the device under dynamic light conditions exceeds the sum of the signals under dynamic dark and static light conditions. By characterizing the surface potential of the material via KPFM and combining the electron‐cloud potential‐well model of contact electrification, a possible theory based on the dual‐electric‐field model is proposed to elucidate the nonlinear photo‐enhancement effect. This study provides insights into the co‐harvesting of mechanical and light energy as well as the exploration of the microscopic mechanism of TVNGs, thereby broadening the application scope of perovskite materials and devices.