Interplay between Intrachain and Interchain Excited States in Donor–Acceptor Copolymers

• DOI: 10.1021/acs.jpcb.1c03989
• Publication Date: 2021-07-05T09:10:12Z
• Authors: Kang Wang; Honggang Chen; Shuangyuan Li; Jinzhong Zhang; Yingping Zou; Ye Yang
• Keywords: Picosecond; Acceptor; Electron donor; Electron acceptor

Recently, rapid progress in the power conversion efficiency for organic solar cells (OSCs) is achieved due to phenomenal development of nonfullerene electron acceptors. In addition pairing donors, conjugated donor–acceptor copolymers are another key player high-efficiency OSCs. Here, temporal evolution excited states a typical copolymer, PM6, was traced by transient absorption spectroscopy. The spectroscopic result implies formation two kinetically correlated intrachain species, polaron excitons and pairs. presence interchain interaction, these species quickly convert into pairs on time scale few picoseconds. Our findings reveal that transfer mechanisms PM6-based OSCs substantially depend PM6 environment bulk heterojunction blends.