Improvement and Regeneration of Perovskite Solar Cells via Methylamine Gas Post-Treatment

The control of film morphology is crucial in achieving high-performance perovskite solar cells (PSCs). Herein, the crystals of the perovskite films are reconstructed by post-treating the MAPbI(3) devices with methylamine gas, yielding a homogeneous nucleation and crystallization of the perovskite in the triple mesoscopic inorganic layers structured PSCs. As a result, a uniform, compact, and crystalline perovskite layer is obtained after the methylamine gas post-treatment, yielding high power conversion efficiency (PCE) of 15.26%, 128.8% higher than that of the device before processing. More importantly, this post-treatment process allows the regeneration of the photo-degraded PSCs via the crystal reconstruction and the PCE can recover to 91% of the initial value after two cycles of the photodegradation-recovery process. This simple method allows for the regeneration of perovskite solar cells on site without reconstruction or replacing any components, thus prolonging the service life of the perovskite solar cells and distinguishing from any other photovoltaic devices in practice.