Planar Benzofuran Inside-Fused Perylenediimide Dimers for High VOC Fullerene-Free Organic Solar Cells

• DOI: 10.1021/acsami.8b19563
• Publication Date: 2019-01-09T00:22:37Z
• Authors: Jing Yang; Fan Chen; Junyi Hu; Yanfang Geng; Qingdao Zeng; Ailing Tang; Xiaochen Wang; Erjun Zhou
• Keywords: HOMO/LUMO; Electron acceptor; Acceptor

Bulk heterojunction organic solar cells based on perylenediimide (PDI) derivatives as electron acceptors have afforded high power conversion efficiency (PCE) but still lagged behind fullerene-based analogues. Design of novel molecular structures by adjusting the PDI ring and/or connection mode remains breakthrough point to improve photovoltaic performance. After introducing benzofuran at inside bay positions and being linked with a single bond fluorene unit, mandatory planar dimers were achieved named FDI2 F-FDI2. Both show high-lying LUMO energy levels realize VOC beyond 1.0 V when using classic polymer PBDB-T an donor. However, F-FDI2 gave totally different performance PCEs 0.15 6.33%, respectively. The central linkage increased miscibility materials ensured much higher short-circuit current because formation suitable phase separation. Our results demonstrated that utilizing skeleton is simple effective strategy achieve high-performance nonfullerene acceptors, modulation conjugated units also vital.