Magnetic Field-Assisted Perovskite Film Preparation for Enhanced Performance of Solar Cells

Perovskite solar cells (PSCs) are promising low-cost photovoltaic technologies with high power conversion efficiency (PCE). The crystalline quality of perovskite materials is crucial to the photovoltaic performance of the PSCs. Herein, a simple approach is introduced to prepare high-quality CH₃NH₃PbI₃ perovskite films with larger crystalline grains and longer carriers lifetime by using magnetic field to control the nucleation and crystal growth. The fabricated planar CH₃NH₃PbI₃ solar cells have an average PCE of 17.84% and the highest PCE of 18.56% using an optimized magnetic field at 80 mT. In contrast, the PSCs fabricated without the magnetic field give an average PCE of 15.52% and the highest PCE of 16.72%. The magnetic field action produces an ordered arrangement of the perovskite ions, improving the crystallinity of the perovskite films and resulting in a higher PCE.