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

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 similar to 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 degrees 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.

Automated summary

Adding potassium hexafluorophosphate can improve the crystallinity, reduce defects, fill the perovskite material, and enhance hydrophobicity in fully-printed mesoscopic perovskite solar cells, resulting in enhanced photoelectric performance and stability.