Enhancing Output Via Electron Transfer at Dielectric-Metal Interface in Triboelectric Nanogenerators

초록

Triboelectric nanogenerators (TENGs) operate fundamentally through electron transfer generated by contact electrification between positively and negatively charged materials and electrostatic induction to form electrical neutrality. This study investigated electron transfer at two critical interfaces: (i) between positively and negatively charged materials and (ii) between polydimethylsiloxane (PDMS), a negatively charged dielectric, and metal electrodes (Mg, Zn, and Ni) with distinct work functions. Band diagram analysis reveals that TENG with PDMS on Mg (TENG-PM) exhibited superior electrical output, attributed to the largest interfacial dielectric-metal junction gap (2.79 eV) at the dielectric-metal junction. To further enhance performance, Mg electrodes were micropatterned by abrasive polishing with #120, #600, and #1000 grit sandpapers, optimizing mechanical stress and facilitating electron transfer as confirmed by FEM simulations. The patterned Mg electrode with #120 grit sandpaper (TENG-PM [#120]) demonstrated the highest output, delivering voltages up to 679.89 V and currents of 20.35 mu A, with a maximum power of 1.64 mW at a matching impedance of 10 M Omega, about 1.50 times higher than the unpatterned TENG-PM (1.09 mW at 6 M Omega). Capacitor charging tests and powering of 100 LEDs demonstrated the practical energy harvesting capability of the optimized devices. These results underscore the critical roles of work function alignment and controlled surface morphology in maximizing electron transfer and improving TENG performance, advancing the development of next-generation energy harvesters for diverse applications.

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