Furfurylammonium as a Spacer for Efficient 2D Ruddlesden-Popper Perovskite Solar Cells

2D perovskites have recently emerged as promising materials for solar cells due to their appealing ambient stability and structural diversity. The organic spacer cation plays an important role in the stability and properties of the 2D perovskites. Herein, a new organic ammonium cation, 2-furfurylammonium (FuMA(+)), is developed as the spacer cation for 2D Ruddlesden-Popper perovskites. Thin films of (FuMA)(2)(MA)(4)Pb5I16 with increased crystal size and enhanced vertical orientation are obtained via an additive-assisted film forming technique, which dramatically improves the efficiency of 2D perovskite solar cells from 4.90% to 15.66%. Moreover, the perovskite films based on FuMA can be prepared in ambient air, and the devices based on the perovskite films prepared in ambient air with 30% relative humidity can perform a power conversion efficiency (PCE) of 15.24%.

Automated summary

2D perovskites are promising materials for solar cells due to their stability and diversity. The organic spacer cation, 2-furfurylammonium (FuMA(+)), plays a crucial role in the stability and performance of 2D perovskites. Thin films of (FuMA)(2)(MA)(4)Pb5I16 were successfully synthesized with increased crystal size and enhanced orientation, leading to a significant improvement in the efficiency of 2D perovskite solar cells. Moreover, these perovskite films can be prepared in ambient air and show high power conversion efficiency (PCE) even at 30% relative humidity.