Remarkably Enhanced Charge Density of Inorganic Material Via Regulating Contact Barrier Difference and Charge Trapping for Triboelectric Nanogenerator

Abstract

AbstractCurrently, the research on improving charge density of charge‐excitation triboelectric nanogenerators (CE‐TENG) mainly focuses on surface modification and thinning of organic polymer materials. However, to increase durability and output, the exploration of high permittivity and high‐thickness inorganic materials is important for extensive applications. Meanwhile, the physical mechanism of air ionization caused by air breakdown during secondary self‐charge excitation (SSCE) needs to be explored. Herein, this study proposes a new strategy for CE‐TENG based on inorganic materials by de‐trapping reverse charge and increasing the contact barrier difference to obtain high charge density and achieve secondary self‐charge excitation. SSCE of three types of films with different leakage currents are evaluated according to their trapping and de‐trapping reverse charges. It is found that the trap distribution of dielectric films with larger leakage currents are mostly shallow‐level traps, whose de‐trapping ability becomes stronger after reverse charge injection. By regulating the contact barrier difference with thin organic polymer on thick inorganic high permittivity material, this study has achieved a high charge density of 1310 µC m−2 with a fast start‐up time of SSCE, which is a new record for the charge density of inorganic materials. This study promotes TENG of inorganic materials toward high‐energy output applications.