Enhanced output performance in paper-based piezoelectric nanogenerators via polarization-engineered Schottky barrier contacts

Abstract

Cellulose, owing to its abundant natural availability and excellent mechanical properties, is considered an ideal alternative to petroleum-based polymers in the fabrication of piezoelectric nanogenerators (PENGs). In this study, we fabricated PENGs with a matrix composed of 80% cellulose and 20% PVDF by mass, incorporating KNN ceramics with varying components as fillers. The films exhibited a dense structure with uniform distribution of KNN fillers, facilitated by hydrogen bonding between the cellulose, PVDF, and KNN. The piezoelectric output performance was significantly enhanced by the piezoelectric polarization-induced Schottky barrier contact and the additional triboelectric contribution from the interaction between the film and PDMS, as elucidated using band theory and two distinct connection modes. Among the PENGs, the C8P2–KNN46 device demonstrated the highest piezoelectric output, achieving a peak power density (P_D) of 12.81 μW cm⁻² under a 10 N force, surpassing most other paper-based PENGs. Furthermore, the contributions of piezoelectric and triboelectric mechanisms were clearly identified. In addition to its impressive piezoelectric performance, the C8P2–KNN46 PENG exhibited excellent mechanical properties, high hydrophobicity, and long-term reliability. Notably, the device was capable of lighting a 3 V LED with simple bending, highlighting its significant potential for next-generation passive devices.