π-Extended Nonfullerene Acceptor for Compressed Molecular Packing in Organic Solar Cells To Achieve over 20% Efficiency

• DOI: 10.1021/jacs.4c01503
• Publication Date: 2024-04-19T12:15:42Z
• Authors: Yuandong Sun; Liang Wang; Chuanhang Guo; Jinyi Xiao; Chenhao Liu; Chen Chen; Weiyi Xia; Zirui Gan; Jingchao Cheng; Jinpeng Zhou; Zhenghong Chen; Jing Zhou; Dan Liu; Tao Wang; Wei Li
• Keywords: Acceptor; Organic semiconductor

Organic photovoltaics (OPVs) suffer from a trade-off between efficient charge transport and suppressed nonradiative recombination due to the aggregation-induced luminance quenching of organic semiconductors. To resolve this grand challenge, π-extended nonfullerene acceptor (NFA) B6Cl with large voids among honeycomb network is designed introduced into photovoltaic systems. We find that presence small amount (i.e., 0.5 or 1 wt %) can compress molecular packing host L8-BO, leading shortened π–π stacking distance 3.59 3.50 Å (that will improve transport) together ordered alkyl chain inhibit energy loss C–C C–H bonds vibrations), as validated by high-energy X-ray scattering measurements. This morphology transformation ultimately results in simultaneously improved JSC, FF, VOC OPVs. As result, maximum PCEs PM6:L8-BO D18:L8-BO are increased 19.1 19.3% 19.8 20.2%, respectively, which highest values for single-junction The university increase performance OPVs further evidenced range polymer:NFA