Li Dandan, Xu Yan, Li Gang, Zhao Wenrong, Da Lin, Zhou Ping, Tang Bo
College of Chemistry, Chemical Engineering and Materials Science, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Institute of Materials and Clean Energy, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan, 250014, P. R. China.
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, P. R. China.
Chemistry. 2025 Mar 12;31(15):e202403972. doi: 10.1002/chem.202403972. Epub 2025 Jan 27.
Non-fused electron acceptors have obtained increasing curiosity in organic solar cells (OSCs) thanks to simple synthetic route and versatile chemical modification capabilities. However, non-fused acceptors with varying quinoxaline core and as-cast device have rarely been explored, and the molecular structure-photovoltaic performance relationship of such acceptors remains unclear. Herein, two non-fused acceptors L19 and L21 with thienyl substituted non-fluorinated/fluorinated quinoxaline core were developed via five-step synthesis. Compared with L19, L21 with F-containing quinoxaline exhibited higher molar extinction coefficient, boosted charge mobility, improved exciton dissociation, more ordered molecular stacking and optimized film morphology. Thereafter, a notable power conversion efficiency (PCE) of 11.45 % could be obtained for the as-cast PBDB-T : L21 -based device, which is significantly better than the device based on PBDB-T : L19 (8.68 %). Furthermore, PM6 : Y6 : L21-based ternary devices were fabricated and exhibited the highest PCE of 17.81 %. This work discloses that the introduction of electron-withdrawing fluorinated quinoxaline core and appropriate side-chain engineering can play an important role in improving the performance of as-cast solar cell devices.
