Recently, A-DA′D-A-type small molecular acceptors (SMAs) with benzo [c][1,2,5]thiadiazole (BT)-fused central cores have shown tremendous progress in organic solar cells (OSCs). In this work, two new BT-fused pentacyclic core based SMAs, namely BTT-4F and BTTCN-Cl, were designed and synthesized. Compared to BTT-4F, BTTCN-Cl not only delivers a reduced bandgap but an elevated lowest unoccupied molecular orbital (LUMO) energy level, which leads to a higher open-circuit voltage (V_OC) and thus a lower energy loss in PM6:BTTCN-Cl-based device. However, PM6:BTT-4F-based OSCs achieves a significantly higher power conversion efficiency (PCE) (10.03%) than that of BTTCN-Cl-based OSCs (6.56%) due to its higher short-circuit density (J_SC) and fill factor (FF). More favorable morphology accompanying with higher and more balanced hole/electron mobilities was obtained in PM6:BTT-4F active layer, which well accounts for the high PCE in BTT-4F-based OSCs.

最近，具有苯并[ c ] [1,2,5]噻二唑（BT）融合中心核的A-DA'DA型小分子受体（SMA）在有机太阳能电池（OSC）中显示出巨大的进步。在这项工作中，设计并合成了两种新的基于BT融合的五环核的SMA，即BTT-4F和BTTCN-Cl。与BTT-4F相比，BTTCN-Cl不仅提供了更小的带隙，而且还提高了最低的未占据分子轨道（LUMO）能量水平，这导致更高的开路电压（V _OC），从而降低了PM6的能量损耗：基于BTTCN-Cl的设备。但是，由于PM6：BTT-4F的OSC具有更高的短路密度（J _SC，因此实现了比BTTCN-Cl的OSC（6.56％）更高的功率转换效率（PCE）（10.03％）。）和填充因子（FF）。在PM6：BTT-4F活性层中获得了更有利的形貌，伴随着更高/更平衡的空穴/电子迁移率，这很好地说明了基于BTT-4F的OSC中的高PCE。