High‐Efficiency All‐Small‐Molecule Organic Solar Cells Based on New Molecule Donors with Conjugated Symmetric/Asymmetric Hybrid Cyclopentyl‐Hexyl Side Chains

• DOI: 10.1002/adfm.202300323
• Publication Date: 2023-03-15T12:03:09Z
• Authors: Xunchang Wang; Zhiya Li; Xufan Zheng; Cong Xiao; Tianyu Hu; Yuchen Liao; Renqiang Yang
• Keywords: Side chain; Acceptor

Abstract All small molecule organic solar cells (ASM‐OSCs) have numerous advantages but lower power conversion efficiencies (PCEs) than their polymer equivalents, which is largely due to the suboptimal nanoscale network structure in a bulk heterojunction (BHJ). Herein, new donors with symmetric/asymmetric hybrid cyclopentyl‐hexyl side chains are designed, accounting for manipulated intermolecular interactions and BHJ morphology. Theoretical experimental results reveal that asymmetric modification has significant influence on potential energy surface interaction can ensure preferable molecular assembly regulate D/A interfacial energetics, thus boosting exciton dissociation charge transport when pairing wide‐used acceptor L8‐BO. Concurrently, bicontinuous interpenetrating optimal domain size be fully evolved layer. As consequence, As‐TCp‐based binary device achieves superior PCE of 16.46% comparison controlled symmetric counterparts S‐BF (14.92%) A‐TCp (15.77%), ranks one best performance among ASM‐OSCs. This study demonstrates precise manipulation cyclo‐alkyl chain combination 2D strategy an effective synergistic approach control phase separation achieving high‐performance