S⋯Cl intramolecular interaction: An efficient strategy to improve power conversion efficiency of organic solar cells

Noncovalent conformational locks (NCLs) including S⋯N, Se⋯O, and S⋯O etc. Have been an effective strategy to improve the planarity and rigidity, and charge transport mobility of organic/polymeric semiconductors. Herein, by replacing methyl group (ITMIC) with chlorine (ITCIC) in the π-bridge, the planarity and rigidity of the π-conjugated skeleton was enhanced by introduction of S⋯Cl NCLs, thus the charge transport mobility was improved accordingly. As a result, PM6:ITCIC based organic solar cells showed impressive PCE of 11.34%, much higher than that based on PM6:ITMIC. This contribution demonstrated a novel kind NCLs (S⋯Cl) for improving the performance of organic solar cells.