Terminally Chlorinated and Thiophene‐linked Acceptor‐Donor‐Acceptor Structured 3D Acceptors with Versatile Processability for High‐efficiency Organic Solar Cells

Abstract

AbstractTo exploit the potential of our newly developed three‐dimensional (3D) dimerized acceptors, a series of chlorinated 3D acceptors (namely CH8‐3/4/5) were reported by precisely tuning the position of chlorine (Cl) atom. The introduction of Cl atom in central unit affects the molecular conformation. Whereas, by replacing fluorinated terminal groups (CH8‐3) with chlorinated terminal groups (CH8‐4 and CH8‐5), the red‐shift absorption and enhanced crystallization are achieved. Benefiting from these, all devices received promising power conversion efficiencies (PCEs) over 16 % as well as decent thermal/photo‐stabilities. Among them, PM6:CH8‐4 based device yielded a best PCE of 17.58 %. Besides, the 3D merits with multi alkyl chains enable their versatile processability during the device preparation. Impressive PCEs of 17.27 % and 16.23 % could be achieved for non‐halogen solvent processable devices prepared in glovebox and ambient, respectively. 2.88 cm2 modules also obtained PCEs over 13 % via spin‐coating and blade‐coating methods, respectively. These results are among the best performance of dimerized acceptors. The decent performance of CH8‐4 on small‐area devices, modules and non‐halogen solvent‐processed devices highlights the versatile processing capability of our 3D acceptors, as well as their potential applications in the future.