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

Abstract

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, PbCl2 modification at the interface of SnO2/CH3NH3PbI3 was used for CH3NH3PbI3-based planar PSCs. The introduction of PbCl2 between SnO2 and CH3NH3PbI3 layers boosted the crystallization of perovskite film, which promoted the photovoltaic properties of corresponding PSCs. The open circuit voltage (VOC) and fill factor (FF) of the PbCl2-modified devices (1 mg/mL) were 1.11 V and 0.79, respectively, which were both higher than those of the reference devices without PbCl2 (1.04 V and 0.76). Moreover, a steady-state power output efficiency exceeding 19% was obtained for the PbCl2-modified devices (1 mg/mL), which implied that PbCl2 modification was an effective and low cost strategy for efficient PSCs.