CC BY-NC-ND 4.0 · Organic Materials 2020; 02(02): 173-181
DOI: 10.1055/s-0040-1709999
Original Article
The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/). (2020) The Author(s).

Effect of Extended π-Conjugation of Central Cores on Photovoltaic Properties of Asymmetric Wide-Bandgap Nonfullerene Acceptors

Tian Xia
a   School of Chemistry, Beihang University, Beijing 100191,China
,
Chao Li
a   School of Chemistry, Beihang University, Beijing 100191,China
,
Hwa Sook Ryu
b   Department of Chemistry, College of Science, Korea University, Seoul 136–713, Republic of Korea
,
Xiaobo Sun
a   School of Chemistry, Beihang University, Beijing 100191,China
,
b   Department of Chemistry, College of Science, Korea University, Seoul 136–713, Republic of Korea
,
a   School of Chemistry, Beihang University, Beijing 100191,China
› Author Affiliations
Funding Information This work was financially supported by the National Natural Science Foundation of China (NSFC: 21734001, 51825301, 21674007). H.Y.W. is grateful for the financial support from the National Research Foundation (NRF) of Korea (NRF-2016M1A2A2940911, 2019R1A6A1A11044070).
Further Information

Publication History

Received: 02 February 2020

Accepted after revision: 12 March 2020

Publication Date:
27 May 2020 (online)


Abstract

Tremendous efforts have been dedicated to develop low-bandgap nonfullerene acceptors (NFAs) for organic solar cells (OSCs). In comparison, the NFAs with a wide bandgap (WBG) have received less attention. Here, three novel acceptor–donor–acceptor type WBG NFAs (TPT-T, TPTT-T, and TPTTT-T) have been designed and synthesized with different fused central cores by varying the π-conjugation length and molecular structures, which all exhibit wide optical bandgaps over 1.8 eV. The successive π-conjugation extension of electron-donating central cores (from TPT-T to TPTT-T and to TPTTT-T) induces red-shifted absorption spectra, lower optical bandgap, and enhanced electron mobility simultaneously. As a result, the optimized OSC devices based on TPTTT-T:PBT1-C achieved a power conversion efficiency of 7.42%, which was higher than those of PBT1-C:TPTT-T (6.93%) and PBT1-C:TPT-T (6.11%) based devices. These results indicate that extending the molecular π-conjugation structure is an effective strategy to design efficient NFAs for OSCs.

Supporting Information

Supporting information for this article is available online at https://doi.org/10.1055/s-0040-1709999.


Supporting Information