Improving and Quantifying Surface Charge Density via Charge Injection Enabled by Air Breakdown

摘要

The modification of triboelectric materials is an important means to improvethe output performance of triboelectric nanogenerator (TENG), and thesurface charge or ion implantation is an effective way among many modificationmethods. However, the output enhancement via optimizing triboelectricmaterials is still limited. Herein, a fast surface charge injection techniquebased on air breakdown effect is reported, which utilizes an excitation circuitto realize the directional accumulation of charge. Consequently, the outputcharge density of the Polyimide (PI) film after charge injection reaches880 μC m~(-2), which is the highest of the series of modified triboelectric materials.Moreover, a novel charge transfer mechanism with electrostatic inductioncompetition is proposed, in which significant difference between surfacecharge density and output charge density is highlighted clearly. Meanwhile,the method of quantifying surface charge density is further given. This workprovides a more effective method for the modification of dielectric materialsand also offers an important insight towards the charge transfer mechanismin TENG.