Boosted Outputs and Robustness of Polymeric Tribovoltaic Nanogenerator Through Secondary Doping

The semiconductor-based tribovoltaic nanogenerator (TVNG) garners distinctive characteristics of direct current output at low internal impedance, rendering it great potentials for self-powered electronics. We present a polymeric TVNG for achieving enhanced electrical outputs and robustness through secondary doping strategy. By utilizing the dimethyl sulfoxide (DMSO) as a dopant, the transport properties of semiconducting poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) can be modulated. We then demonstrate that the tribovoltaic outputs can be significantly enhanced due to the improved conductivity of the PEDOT:PSS and the enlarged Schottky barrier at the dynamic metal-semiconductor interfaces. The quantity of the transferred charge per motion cycle can reach 150.48 mC m-2 in contact-separation mode and 225.73 mC m-2 in sliding mode. Meantime, the dopant improves the flexibility of the PEDOT:PSS and hence the mechanical robustness of TVNG, allowing stable outputs for ~100,000 contact-separation operations cycles or ~36,000 bending cycles. Furthermore, the device also demonstrates exceptional humidity resistance, but confirms a coupling of tribovoltaic effect and electrochemical effect in high-humidity conditions (relative humidity over 90%). Therefore, our findings provide insightful strategies for future optimization of practical tribovoltaic devices.