PDI-based heteroacenes as acceptors for fullerene-free solar cells: importance of their twisted geometry. (20th July 2020)

• Record Type: Journal Article
• Authors: Chen, Huaqing; Wang, Ling; Sun, Hua; Liu, Qian; Tan, Xiao; Sang, Shenglong; Wu, Bo; Zhang, Cong; Chen, Fei; Hang, Xiao-Chun; Chen, Zhi-Kuan
• Is Part Of: New journal of chemistry. Volume 44:Number 30(2020)
• Page Start: 13093
• Page End: 13099
• Publication Date: 2020-07-20
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d0nj01733g
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Two novel PDI-based small molecules with twisted geometry were designed and synthesised as acceptors for organic solar cells. Abstract : Two perylenediimide (PDI) derivatives (FP4 TT2T and FP4 3T) with extended conjugation have been successfully synthesized. Due to their long fused D–A (D: donor and A: acceptor) molecular structures, PDI-based heteroacenes have rigid backbones and exhibit strong light absorption in the 300–600 nm range. With the contribution from the PDI moiety with strong electron affinity, the molecules possess low energy levels of LUMOs ( ca. −3.7 eV), fitting well as acceptors for fullerene-free organic solar cells (OSCs). OSC devices containing FP4 TT2T and FP4 3T were fabricated and fully characterized. It is found that the geometric twist in PDI-based heteroacenes as acceptors could enhance the performance of OSC devices. OSCs based on FP4 3T with a more twisted geometry achieved a power conversion efficiency of 6.05%, which is higher than those based on the FP4 TT2T counterpart.