Asymmetric Acceptors Enabling Organic Solar Cells to Achieve an over 17% Efficiency: Conformation Effects on Regulating Molecular Properties and Suppressing Nonradiative Energy Loss

Wei Gao, Huiting Fu, Yuxiang Li, Francis Lin, Rui Sun, Ziang Wu, Xin Wu, Cheng Zhong, Jie Min, Jingdong Luo, Han Young Woo, Zonglong Zhu, Alex K.Y. Jen

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Y6, as a state-of-the-art nonfullerene acceptor (NFA), is extensively optimized by modifying its side chains and terminal groups. However, the conformation effects on molecular properties and photovoltaic performance of Y6 and its derivatives have not yet been systematically studied. Herein, three Y6 analogs, namely, BP4T-4F, BP5T-4F, and ABP4T-4F, are designed and synthesized. Owing to the asymmetric molecular design strategies, three representative molecular conformations for Y6-type NFAs are obtained through regulating the lateral thiophene orientation of the fused core. It is found that conformation adjustment imposes comprehensive effects on the molecular properties in neat and blend films of these NFAs. As a result, organic solar cells (OSCs) fabricated with PM6:BP4T-4F, PM6:BP5T-4F, and PM6:ABP4T-4F show high power conversion efficiency of 17.1%, 16.7%, and 15.2%, respectively. Interestingly, these NFAs with different conformations also show reduced energy loss (Eloss) in devices via gradually suppressed nonradiative Eloss. Moreover, by employing a selenium-containing analog, CH1007, as the complementary third component, ternary OSCs based on PM6:BP5T-4F:CH1007 (1:1.02:0.18) achieve a 17.2% efficiency. This work helps shed light on engineering the molecular conformation of NFAs to achieve high efficiency OSCs with reduced voltage loss.

Original languageEnglish
JournalAdvanced Energy Materials
DOIs
Publication statusAccepted/In press - 2020

Keywords

  • asymmetric acceptors
  • conformation effects
  • energy loss
  • organic solar cells

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

Fingerprint Dive into the research topics of 'Asymmetric Acceptors Enabling Organic Solar Cells to Achieve an over 17% Efficiency: Conformation Effects on Regulating Molecular Properties and Suppressing Nonradiative Energy Loss'. Together they form a unique fingerprint.

Cite this