The coupled effects of an electron blocking layer beneath tribomaterials for boosted triboelectric nanogenerators

Triboelectric nanogenerators (TENGs) have been studied from 2012 to help increase output performance. However, most studies are focused on negatively charged tribomaterials for high output performance. This study demonstrates the possibility of boosted triboelectric output performance by embedding an electron blocking layer (EBL) at the interface between electrode polymers in positively charged tribomaterials as well as negatively charged tribomaterials, as a coupled effect. We used TiO_x with a high dielectric constant as an EBL and analyzed the orbital structure of TiO_x to verify levels of charge transfer with different thicknesses of TiO_x. As a result, we achieved the output performance (121.2 V, 5.1 µA) of a TENG by inserting a TiO_x-EBL-100 nm with 2.5 Hz, 5 N, which is an increase of as much as eight times compared to the output performance without the TiO_x-EBL. The increase in the output performance of the TENG is attributed not only to the excellent charge transport of the TiO_x-EBL but also to the additive polarization in the electric field surface. We suggest this result presents a strategy to improve the output performance through the polymer used as both the positively charged material and a negatively charged material by embedding the ETL.