Stable power output (PCE>19%) of planar perovskite solar cells with PbCl2 modification at the interface of SnO2/CH3NH3PbI3

Interfacial modification as a feasible strategy to improve the properties of perovskite solar cells (PSCs) has been widely studied in recent years. In this work, PbCl 2 modification at the interface of SnO 2 /CH 3 NH 3 PbI 3 was used for CH 3 NH 3 PbI 3 -based planar PSCs. The introduction of PbCl 2 between SnO 2 and CH 3 NH 3 PbI 3 layers boosted the crystallization of perovskite film, which promoted the photovoltaic properties of corresponding PSCs. The open circuit voltage ( V OC ) and fill factor (FF) of the PbCl 2 -modified devices (1 mg/mL) were 1.11 V and 0.79, respectively, which were both higher than those of the reference devices without PbCl 2 (1.04 V and 0.76). Moreover, a steady-state power output efficiency exceeding 19% was obtained for the PbCl 2 -modified devices (1 mg/mL), which implied that PbCl 2 modification was an effective and low cost strategy for efficient PSCs.