Selenium-Driven Charge Delocalization in Conjugated Polymers Enables High Thermoelectric Performance
Yuqian Liu , Chenyu Han , Ruilin Zheng , Wanlu Zhang , Xia Guo , Maojie Zhang , Guangzheng Zuo
Chinese Journal of Chemistry ›› 2026, Vol. 44 ›› Issue (3) : 319 -327.
Achieving high electrical conductivity through doping without compromising the Seebeck coefficient remains a fundamental challenge in organic thermoelectrics, owing to the intrinsic trade-off between the two parameters. Here, we propose a rational molecular design strategy to enhance the charge delocalization by substituting thiophene with selenophene in donor-acceptor (D-A) type of conjugated polymers based on benzo[1,2-b:4,5-b']dithiophene (BDT) and diketone-functionalized benzo[1,2-c:4,5-c']dithiophene (BDD) units. The selenophene substitution, combined with backbone planarization via a phenyl substituent, increases the charge localization length from ~7 nm to ~11.5 nm. These structural modifications result in a significant improvement of electrical conductivity, from ~78 S cm–1 to ~148 S cm–1, while maintaining a high Seebeck coefficient, leading to a maximum power factor exceeding 130 μW·m–1·K–2. These results highlight selenium-driven charge delocalization as a promising approach to modulating charge transport and guide the molecular design of efficient organic thermoelectrics.
Conjugated polymers / Organic thermoelectrics / Charge transport / Charge delocalization / Localization length / Selenium / p-Doping / Seebeck coefficient
2025 SIOC, CAS, Shanghai, & WILEY-VCH GmbH
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