Two core-expanded naphthalenediimide (NDI) derivatives NDI3HU-DTYM2 (1) and (DTYM-NDI-DTYA)₂ (2) with coplanar and twisted molecular backbones, respectively, were used as low-temperature solution-processed electron transport materials (ETMs) for CH₃NH₃PbI₃-based inverted planar perovskite solar cells (PSCs). The high electron mobility as well as low-lying lowest unoccupied molecular orbital (LUMO) energy levels and good film-formation ability on perovskite layers make 1 and 2 both promising ETMs for PSCs. The PSCs devices based on 1 show a power conversion efficiency (PCE) of 8.7%, while the PSCs devices based on 2 that has twisted molecular backbone exhibit a PCE value of up to 12.9%, a short-circuit current density (J_sc) value of 22.80 mA cm⁻² with negligible hysteresis, which is comparable to that of PCBM-based PSCs devices. Our results demonstrate that core-expanded NDI-based n-type organic semiconductors, especially those with twisted molecular backbones, have great potential for high-performance, low-cost, solution-processed non-fullerene ETMs in PSCs.

分别使用具有共平面分子和扭曲分子骨架的两种核扩展的萘二甲酰亚胺（NDI）衍生物NDI3HU-DTYM2（1）和（DTYM-NDI-DTYA）₂（2）作为低温溶液处理的电子传输材料（ETM） ）用于基于CH ₃ NH ₃ PbI ₃的倒置平面钙钛矿太阳能电池（PSC）。高钙离子迁移率以及低位最低的最低未占据分子轨道（LUMO）能级和钙钛矿层上良好的成膜能力使PSC的ETM成为1和2。基于1的PSC设备显示出8.7％的功率转换效率（PCE），而基于2的具有扭曲分子主链的PSCs器件则显示出高达12.9％的PCE值，22.80 mA cm的短路电流密度（J _sc）值^{- 2的}磁滞可以忽略不计，这与基于PCBM的PSC器件的磁滞相当。我们的结果表明，核扩展的基于NDI的n型有机半导体，尤其是那些具有扭曲分子主链的有机半导体，在PSC中具有高性能，低成本，溶液处理的非富勒烯ETM的巨大潜力。