Enhancing the Efficiency and Stability of Perovskite Solar Cells through Defect Passivation and Controlled Crystal Growth Using Allantoin.

In this study, we present a robust approach that concurrently manages crystal growth and defect passivation within the perovskite layer through the introduction of a small molecule additive─allantoin. The precise regulation of crystal growth in the presence of allantoin yields perovskite films characterized by enhanced morphology, larger grain size, and improved grain orientation. Notably, the carbonyl and amino groups present in allantoin passivate under-coordinated Pb and I defects, respectively, through molecular interactions.