The black phase formamidinium lead iodide perovskite (α-FAPbI3) undergoes an undesired transformation to a non-perovskite δ-phase, rendering it inactive. Here authors show the significant role of inherent iodine defects in accelerating phase transition kinetics and exacerbating α-FAPbI3 instability.
- Yuhang Liang
- Feng Li
- Rongkun Zheng
