Mainstream organic solar cells (OSCs) suffer a great variation of photovoltaic performance among different batches of polymers, which brings an opportunity for all-small-molecule OSCs to take leading position of industrialization. In recent years, benzodithiophene terthiophene rhodamine (BTR), as small molecule donor, has played an important role in this field. Here we investigated two typical BTR based all-small-molecule OSCs processed with different annealing methods, to explore the morphology optimization brought by them. As a result, BTR:PC₇₁BM system was optimized by solvent vapor annealing (SVA) reaching an excellent fill factor (FF) of 79.1% via tuning molecular packing intensity, while BTR:Y6 with temperature annealing (TA) yielded a power conversion efficiency (PCE) of 12.125% whose molecular packing orientation had been changed. Additionally, by crossing using SVA and TA methods, we found that these two method can't be utilized together to further improve the PCE for either system. Therefore, our work offers better PCEs for these two reported combinations and further studies the compatibility between specific BTR based active layers and designated annealing methods, providing deeper understanding of device engineering on all-small-molecule OSCs.

主流有机太阳能电池（OSC）在不同批次的聚合物中的光伏性能差异很大，这为全小分子OSC占据了工业化的领先地位提供了机会。近年来，作为小分子供体的苯并二噻吩，特噻吩若丹明（BTR）在该领域发挥了重要作用。在这里，我们研究了两种典型的基于BTR的全小分子OSC，它们采用不同的退火方法处理，以探索它们带来的形态优化。结果，BTR：PC ₇₁ BM系统通过溶剂蒸汽退火（SVA）达到了极佳的填充系数（FF）通过调节分子堆积强度达到79.1％），而采用温度退火（TA）的BTR：Y6产生了12.125％的功率转换效率（PCE），其分子堆积方向已经改变。此外，通过使用SVA和TA方法进行交叉，我们发现这两种方法不能一起使用来进一步改善任一系统的PCE。因此，我们的工作为这两种报告的组合提供了更好的PCE，并进一步研究了基于BTR的特定活性层与指定退火方法之间的兼容性，从而提供了对全小分子OSC器件设计的更深入了解。