Abstract
The incorporation of electron-withdrawing substituents is one of the promising approaches to enhance the photovoltaic characteristics of p-type polymer donors. In this study, three benzothiadiazole (BT)-based D–A-type conjugated polymers decorated with different electron-withdrawing substituents were synthesized to understand the optimum constitution. First, a fluorinated alkylthienyl-substituted benzodithiophene donor was coupled with the BT acceptor via an alkylated thiophene bridge to yield the PB-BT reference. Subsequently, PB-BT was structurally modified by introducing strong electron-withdrawing F and CN units at the 5-position of the BT acceptor to afford two target polymers, PB-BTF and PB-BTCN, respectively. The optical, electrochemical, and photovoltaic properties of the three polymers were strongly dependent on the electron-withdrawing substituents. Notably, the polymer solar cell based on PB-BTF adopting the nonfullerene acceptor exhibited the highest power conversion efficiency (PCE) of 11.12 %, while those based on PB-BT and PB-BTCN exhibited PCEs of 9.56 % and 5.07 %, respectively. These results indicate that the choice of appropriate electron-withdrawing substituents is of great importance for developing high-performance BT-based D–A-type polymers.
Original language | English |
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Article number | 115778 |
Pages (from-to) | 1-8 |
Number of pages | 8 |
Journal | Optical Materials |
Volume | 154 |
DOIs | |
Publication status | Published - Aug 2024 |
Keywords
- Electron-withdrawing substituent
- Benzothiadiazole
- Benzodithiophene
- Polymer solar cell
- Nonfullerene