Efficient and easily repeatable organic solar cells in a high boiling point solvent by introducing a highly mixed tolerant guest acceptor

Abstract

Organic solar cells (OSCs) with low-temperature solution processing have attracted extensive research interest. To achieve good phase separation and molecular nucleation crystallization, the active layer usually needs to be processed with low boiling point solvents, which narrows the processing window and limits the implementation of industrial printing processes. Herein, we synthesized a novel non-fullerene acceptor L8BO-2O as a third component to regulate the performance of the classical PM6:Y6 system in high boiling point solvents. L8BO-2O, with an alkoxy chain, can effectively suppress the aggregation effect of active materials, which is beneficial for achieving appropriate phase separation in high-boiling solvent film-forming processes. Additionally, the similar structure and stacking distance between L8BO-2O and Y6 can effectively improve the mixing tolerance of the host and guest, achieve more effective energy transfer and alloy working mechanisms, thereby greatly increasing light utilization and charge extraction. Finally, the efficiency of the champion ternary OSC reached 16.4% with the doping of 20 wt% L8BO-2O, and the efficiencies of all the ternary OSCs were significantly improved over a wide range of doping (0–80 wt%). This result emphasizes the feasibility of introducing a suitable third component to achieve efficient and reproducible OSCs in high boiling point solvents.