p‑n Junction Based Direct-Current Triboelectric\nNanogenerator by Conjunction of Tribovoltaic Effect and Photovoltaic\nEffect

Abstract

Triboelectric nanogenerators (TENGs)\nhave attracted much interest\nin recent years, due to its effectiveness and low cost for converting\nhigh-entropy mechanical energy into electric power. The traditional\nTENGs generate an alternating current, which requires a rectifier\nto provide a direct-current (DC) power supply. Herein, a dynamic p-n\njunction based direct-current triboelectric nanogenerator (DTENG)\nis demonstrated. When a p-Si wafer is sliding on a n-GaN wafer, carriers\nare generated at the interface and a DC current is produced along\nthe direction of the built-in electric field, which is called the\ntribovoltatic effect. Simultaneously, an UV light is illuminated on\nthe p-n junction to enhance the output. The results indicate that\nthe current increases 13 times and the voltage increases 4 times under\nUV light (365 nm, 28 mW/cm²) irradiation. This work demonstrates\nthe coupling between the tribovoltaic effect and the photovoltaic\neffect in DTENG semiconductors, promoting further development for\nenergy harvesting in mechanical energy and photon energy.