Fused Hexacyclic Nonfullerene Acceptor with Strong Near-Infrared Absorption for Semitransparent Organic Solar Cells with 9.77% Efficiency

Wei Wang; Cenqi Yan; Tsz-Ki Lau; Jiayu Wang; Kuan Liu; Yan Fan; Xinhui Lu; Xiaowei Zhan

doi:10.1002/adma.201701308

Fused Hexacyclic Nonfullerene Acceptor with Strong Near-Infrared Absorption for Semitransparent Organic Solar Cells with 9.77% Efficiency

Adv Mater. 2017 Aug;29(31). doi: 10.1002/adma.201701308. Epub 2017 Jun 13.

Authors

Wei Wang¹, Cenqi Yan¹, Tsz-Ki Lau², Jiayu Wang¹, Kuan Liu¹, Yan Fan¹, Xinhui Lu², Xiaowei Zhan¹

Affiliations

¹ Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.
² Department of Physics, Chinese University of Hong Kong, New Territories, Hong Kong, China.

PMID: 28608531
DOI: 10.1002/adma.201701308

Abstract

A fused hexacyclic electron acceptor, IHIC, based on strong electron-donating group dithienocyclopentathieno[3,2-b]thiophene flanked by strong electron-withdrawing group 1,1-dicyanomethylene-3-indanone, is designed, synthesized, and applied in semitransparent organic solar cells (ST-OSCs). IHIC exhibits strong near-infrared absorption with extinction coefficients of up to 1.6 × 10⁵ m^-1 cm^-1 , a narrow optical bandgap of 1.38 eV, and a high electron mobility of 2.4 × 10^-3 cm² V^-1 s^-1 . The ST-OSCs based on blends of a narrow-bandgap polymer donor PTB7-Th and narrow-bandgap IHIC acceptor exhibit a champion power conversion efficiency of 9.77% with an average visible transmittance of 36% and excellent device stability; this efficiency is much higher than any single-junction and tandem ST-OSCs reported in the literature.

Keywords: dithienocyclopentathieno[3,2-b]thiophene; fused-ring electron acceptors; near-infrared absorption; nonfullerene acceptors; organic solar cells.