Efficient and stable full-printed mesoscopic perovskite solar cells with potassium hexafluorophosphate additives

Abstract

Full-printed mesoscopic perovskite solar cells (MPSCs) have great potential in commercial applications because of their screen-printing process and excellent stability; however, the defect and filling issues in MPSCs still limit device performance. Here, an efficient passivation strategy with potassium hexafluorophosphate (KPF₆) as an additive is proposed to overcome the above issues. The properties of the films and the corresponding performances of MPSCs with KPF₆ are systemically investigated. The results show the crystallinity, defect issues, filling of the perovskite in the mesoporous structure and hydrophobicity of the MPSCs are all improved with KPF₆ introduction, which results in the inhabitation of non-radiative recombination loss, and raises the photoelectric performance and stability. With the KPF₆ additive in the MPSCs, the power conversion efficiency (PCE) of the champion devices reached 15.39%, which is significantly raised by ∼10% against that of the control devices (14.16%). The unencapsulated MPSCs with KPF₆ maintain 95% of their initial PCE after 50 days stored in air (25 ± 5 °C @ 50 ± 5% RH), while the MPSCs without KPF₆ only maintain 80% of their initial PCE. This work provides an effective passivation strategy to improve the PCE and stability of MPSCs.