Enhancing organic solar cell efficiency with ester-based quinoxaline non-fullerene acceptors in ternary blends

The ternary strategy has been recognized as an effective approach for boosting the power conversion efficiency (PCE) of organic solar cells (OSCs). For ternary devices, selecting an appropriate third component is critical to ensure that both the photocurrent and voltage outputs of OSCs are not compromised. In this study, we present the use of an ester-based quinoxaline core non-fullerene acceptor (QEIP-4Cl) for the fabrication of ternary devices, which demonstrate enhanced absorption spectra and beneficial cascading LUMO energy level arrangement when paired with the PM6:L8-BO blend. Compared to the binary system, the ternary blend system exhibits superior thin-film phase separation and better suppression of non-radiative recombination, resulting in a reduced energy loss (E_loss) value. Moreover, by prolonging exciton lifetime, promoting charge carrier migration and suppressing charge recombination to facilitate improved J_SC in OSCs. With the combined enhancement of V_OC and J_SC, OSCs achieve an impressive efficiency of 19.27 %. This research demonstrates the effectiveness of the ternary strategy in enhancing the performance of OSCs. The careful selection of the third component contributes to improved absorption, energy level alignment, and overall efficiency, making it a notable advancement in organic solar cell technology.