The Combination of S⋯N and S⋯Cl Noncovalently Conformational Locks for
Constructing High-Planarity and Low-Cost Non-fused-Ring Electron
Acceptors
Abstract
By employing thiazole and 4-chlorothiazole as the A′ units, two
A-D-A′-D-A type nonfused-ring electron acceptors (NFREAs) Tz-H
and Tz-Cl were designed and synthesized. Replacing thiazole in
Tz-H with 4-chlorothiazole can not only remarkably shorten the
synthetic route through C-H direct arylation but also enhance molecular
planarity with the simultaneous incorporation of S···N and S···Cl
non-covalently conformational locks (NoCLs). The photovoltaic devices
based on PM6:Tz-Cl exhibited a power conversion efficiency as
high as 11.10%, much higher than that of PM6:Tz-H (6.41%),
mainly due to more efficient exciton dissociation, better and more
balanced carrier mobility, less charge recombination, and more favorable
morphology. These findings demonstrate the great potential of NoCLs in
achieving low-cost and high-performance NFREAs.