Significant Enhancement in Performance and Durability of Near-Infrared Reflective Flexible Triboelectric Nanogenerators Through Surface Modification Strategy via Self-Assembled Monolayers

Abstract

Although triboelectric nanogenerators (TENG) have been explored as a promising candidate for applications in multifunctional intelligent systems, the realization of highly efficient TENG that synchronously possess reasonable light transparency, high near-infrared reflectivity against solar heat gain, and good mechanical flexibility still remains challenging. Here, we present a reliable strategy that can substantially boost the performance and durability of indium tin oxide (ITO)-free transparent flexible TENG by surface modification via self-assembled monolayers (SAM). Through the modification of Sb₂O₃/Ag/Sb₂O₃ electrode and polydimethylsiloxane (PDMS) dielectric layer with SAM of 12-(dodecylphosphonic acid) triethyl ammonium bromide and perfluorinated molecules, respectively, triboelectric charge generation is facilitated due to relatively large work function (WF) difference between the tribolayers. The resulting flexible TENG not only afford record-breaking power density (27.28 W/m²) for ITO-free transparent flexible TENG, but also possess high durability against 5,000 cycles of bending owing to good adhesion at the SAM/substrate interfaces and high robustness of electrode. More encouragingly, the use of Sb₂O₃/Ag/Sb₂O₃ electrode endows TENG with both reasonable light transparency and high near-infrared reflectivity, which is beneficial against heat gain from solar radiation. This work showcases a promising route towards realizing transparent flexible TENG with high performance and durability, which represents a new platform for the design of next-generation wearable electronics.

Keywords: ITO‐free electrode; flexible devices; surface modification; triboelectric nanogenerators.