All-small-molecule organic solar cells with good batch-to-batch reproducibility combined with non-halogen solvent processing show great potential for commercialization. However, non-halogen solvent processing of all-small-molecule organic solar cells are rarely reported and its power conversion efficiencies are very difficult to improve. Herein, we designed and synthesized a small molecule donor BM-ClEH that can take advantage of strong aggregation property induced by intramolecular chlorine-sulfur non-covalent interaction to improve molecular pre-aggregation in tetrahydrofuran and corresponding micromorphology after film formation. Tetrahydrofuran-fabricated all-small-molecule organic solar cells based on BM-ClEH:BO-4Cl achieved high power conversion efficiencies of 15.0% in binary device and 16.1% in ternary device under thermal annealing treatment. In contrast, weakly aggregated BM-HEH without chlorine-sulfur non-covalent bond is almost inefficient under same processing conditions due to poor pre-aggregation induced disordered π-π stacking, indistinct phase separation and exciton dissociation. This work promotes the development of non-halogen solvent processing of all-small-molecule organic solar cells and provides further guidance.

具有良好批次重现性的全小分子有机太阳能电池与非卤素溶剂加工相结合，显示出巨大的商业化潜力。然而，全小分子有机太阳能电池的无卤溶剂加工鲜有报道，其光电转换效率也很难提高。在此，我们设计并合成了一种小分子供体BM-ClEH，它可以利用分子内氯-硫非共价相互作用诱导的强聚集特性来改善分子在四氢呋喃中的预聚集以及成膜后相应的微形貌。基于BM-ClEH:BO-4Cl的四氢呋喃制造的全小分子有机太阳能电池在热退火处理下实现了二元器件15.0%和三元器件16.1%的高功率转换效率。相比之下，没有氯硫非共价键的弱聚集BM-HEH在相同的加工条件下几乎是低效的，因为预聚集不良导致无序π-π堆积、不明显的相分离和激子解离。该工作促进了全小分子有机太阳能电池无卤溶剂加工的发展，并提供了进一步的指导。