Backbone Coplanarity Tuning of 1,4-Di(3-alkoxy-2-thienyl)-2,5-difluorophenylene-Based Wide Bandgap Polymers for Efficient Organic Solar Cells Processed from Nonhalogenated Solvent

Qiaogan Liao; Kun Yang; Jianhua Chen; Chang Woo Koh; Yumin Tang; Mengyao Su; Yang Wang; Yinhua Yang; Xiyuan Feng; Zhubing He; Han Young Woo; Xugang Guo

doi:10.1021/acsami.9b09692

Backbone Coplanarity Tuning of 1,4-Di(3-alkoxy-2-thienyl)-2,5-difluorophenylene-Based Wide Bandgap Polymers for Efficient Organic Solar Cells Processed from Nonhalogenated Solvent

ACS Appl Mater Interfaces. 2019 Aug 28;11(34):31119-31128. doi: 10.1021/acsami.9b09692. Epub 2019 Aug 16.

Authors

Qiaogan Liao¹, Kun Yang, Jianhua Chen, Chang Woo Koh², Yumin Tang, Mengyao Su, Yang Wang, Yinhua Yang, Xiyuan Feng, Zhubing He, Han Young Woo², Xugang Guo

Affiliations

¹ School of Materials Science and Engineering , Harbin Institute of Technology , Harbin 150001 , China.
² Department of Chemistry , Korea University , Seoul 136-713 , Republic of Korea.

PMID: 31382736
DOI: 10.1021/acsami.9b09692

Abstract

Halogenated solvents are prevailingly used in the fabrication of nonfullerene organic solar cells (NF-OSCs) at the current stage, imposing significant restraints on their practical applications. By copolymerizing phthalimide or thieno[3,4-c]pyrrole-4,6-dione (TPD) with 1,4-di(3-alkoxy-2-thienyl)-2,5-difluorophenylene (DOTFP), which features intramolecular noncovalent interactions, the backbone planarity of the resulting DOTFP-based polymers can be effectively tuned, yielding distinct solubilities, aggregation characters, and chain packing properties. Polymer DOTFP-PhI with a more twisted backbone showed a lower degree of aggregation in solution but an increased film crystallinity than polymer DOTFP-TPD. An organic thin-film transistor and NF-OSC based on DOTFP-PhI, processed with a nonhalogenated solvent, exhibited a high hole mobility up to 1.20 cm² V^-1 s^-1 and a promising power conversion efficiency up to 10.65%, respectively. The results demonstrate that DOTFP is a promising building block for constructing wide bandgap polymers and backbone coplanarity tuning is an effective strategy to develop high-performance organic semiconductors processable with a nonhalogenated solvent.

Keywords: backbone coplanarity; noncovalent interaction; nonfullerene organic solar cells; nonhalogenated solvent; organic field-effect transistors.