Tuning the performance of ferroelectric polymer-based triboelectric nanogenerator

Triboelectric nanogenerators are devices that can transform mechanical energy into electrical energy, and regulating their performance is critical for energy harvesting applications and other applications where they act as sensors. In the present work, we have fabricated a ferroelectric PVDF-NaNbO3 nanocomposite film-based triboelectric nanogenerator and demonstrated a large tuning (64%) of the output of the triboelectric nanogenerator by adjusting its electrical polarization state. The triboelectric nanogenerator fabricated using a negatively polarized PVDF-NaNbO3 nanocomposite film has an instantaneous output power of 0.17 mW, which is significantly higher than the triboelectric nanogenerator fabricated using a positively polarized PVDF-NaNbO3 nanocomposite film, which has an output power of 0.06 mW. Kelvin probe force microscopy measurements were carried out to explore the cause of the change in the output with the change in the polarization state of the films. The work function of the PVDF-NaNbO3 film is found to change with the polarization of the film, which resulted in the change in the output. More explanation of the effect of the polarization state on the performance of the triboelectric nanogenerator has been presented using an electronic energy level diagram of the contacting materials. The current work demonstrated the advantage of using ferroelectric polymers for triboelectric nanogenerator applications, because the output performance of the triboelectric nanogenerator can be tuned as per requirement.