There has been significant progress with regard to research on nonfullerene small molecule acceptors (SMAs) during the past several years. Typically, high-performance nonfullerene SMAs are based on symmetric A-D-A or A-π-D-π-A structural frameworks. In this study, a novel asymmetric nonfullerene SMA, TTPT-T-2F, with an A-D-π-A structure is rationally designed and synthesized. In addition, a symmetric A-D-A-type nonfullerene SMA, IT-2F, and a symmetric A-π-D-π-A-type nonfullerene SMA, T-TPT-T-2F, are also synthesized for comparison. When PBT1-C is employed as a polymer donor, a promising power conversion efficiency (PCE) of 12.71% is achieved for TTPT-T-2F-based organic solar cells (OSCs), which surpasses those of devices based on IT-2F (PCE = 10.54%) and T-TPT-T-2F (PCE = 10.71%). Favorable phase separation toward efficient and more balanced charge transport accounts for the higher PCE achieved in the PBT1-C:TTPT-T-2F device. Our results demonstrate that a small molecule acceptor with an A-D-π-A structural framework is a promising class of nonfullerene acceptors for OSCs.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)