Gradient Ion Beams Regulate Surface Group Modification to Enhance Interfacial Charge Transport in Triboelectric Polymers

Triboelectric nanogenerators (TENGs) exhibit high sensitivity and flexibility, enabling them to rapidly and effectively respond to high-entropy mechanical energy sources like friction and contact into utilizable electrical power, TENGs are emerging as one of the most promising devices for future applications in wearable devices and self-powered sensors. However, the flexible polymers charging materials used in TENGs inherently suffer from low surface charge density, which significantly constrains their electrical performance. This study proposed a gradient ion beam irradiation strategy to engineer functional groups on polymer surfaces through precise dose-control irradiation, thereby enhancing interfacial charge transport capability. Electrical testing revealed 13-, 10-, and 7-fold improvements in output voltage, current, and surface charge density, respectively, with stability exceeding 1440-fold that of pure charge injection. Chemical structural evolution under varying irradiation doses was systematically investigated to probe molecular-scale regulatory mechanisms. Combining density functional theory (DFT) calculations, we found that the energy bandgap of the surface molecular structure decreased after irradiation, and the distribution of the electrostatic surface potential (ESP) indicated an increase in electron energy, thereby elucidating the mechanism underlying the enhanced surface charge transport in charged polymers. Meanwhile, after being fabricated into micro-devices, they exhibit high sensitivity and excellent abrasion resistance, establishing a theoretical foundation for advancing TENG functionality in wearable sensors and flexible electronics.