Management of an intermediate phase via a multifunctional dietary supplement for efficient and stable perovskite solar cells

Perovskite crystal growth regulation is a promising approach to obtaining high-quality perovskite films for boosting the application of the corresponding photovoltaic devices. However, complex nucleation paths frequently lead to low crystal quality with high defect density and poor crystal growth orientation of the perovskite film. Herein, a multifunctional dietary supplement, glucosamine hydrochloride (GluACl), is incorporated into the perovskite precursors to form a new intermediate phase to modulate the crystal growth during the film-forming process. Specifically, the incorporated GluACl in the perovskite precursors significantly avoids the phenomenon of competitive nucleation and the crystallization rate is retarded. The prepared perovskite films show better crystal quality with fewer defects and preferred orientation using this strategy. The correlative crystallization kinetics of the perovskite upon addition of GluACl is demonstrated by a series of in situ characterizations. Meanwhile, by combining the single-crystal structure of (GluA)(PbI3)center dot 3DMSO with Density Functional Theory (DFT) calculations, the growth mechanism of the perovskite film with GluACl is reasonably explained. Remarkably, the target device achieved an efficiency approaching 24% with a high V-OC of 1.20 V. Additionally, the optimized devices show much improved environmental stability. This work adds key building blocks to regulate crystallization and passivate defects toward highly efficient and stable PVSCs by employing natural molecules.