Organic thermoelectrics have attracted considerable attention owing to their remarkable advantages, including room-temperature power generation, skin-attachable/wearable applications with biocompatibility, and solution-based high-throughput fabrication. Self-doped conjugated polyelectrolytes (CPEs) constitute a promising class of conductive organic materials that are considered potential candidates for organic thermoelectrics. However, the low power factor of CPEs derived from their low electrical conductivity (σ) has been a major drawback in CPE-based thermoelectrics. Herein, we report a strategy for enhancing the thermoelectric performance of CPEs through a post-treatment using aq. H2SO4 solution. The post-treatment increases σ by two orders of magnitude, originating from H2SO4-induced doping accompanying a significant increase in charge carrier concentration. Consequently, a power factor of 3.0 W m‒1 K‒2 is achieved at room temperature. Furthermore, using this highly conductive H2SO4-doped CPE, we developed flexible thermoelectric generators that allow durable power generation under repetitive mechanical bending stresses. Our findings provide insight into developing high-performance and versatile CPEs for next-generation organic thermoelectrics.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): CRG2018-3737., OSR-CRG2018-3737
Acknowledgements: D.B. acknowledges KAUST Solar Center Competitive Fund (CCF) for financial support. H.Y.W. is grateful for the financial support from the National Research Foundation (NRF) of Korea (2017K2A9A2A12000315, 2019R1A2C2085290). This report is based upon work
supported by the King Abdullah University of Science and Technology (KAUST) Office of Sponsored Research (OSR) under Award No. OSR-CRG2018-3737.