Toward stabilization of formamidinium lead iodide perovskites by defect control and composition engineering.

ABSTRACT: Phase instability poses a serious challenge to the commercialization of formamidinium lead iodide (FAPbI₃)-based solar cells and optoelectronic devices. Here, we combine density functional theory and machine learning molecular dynamics simulations, to investigate the mechanism driving the undesired α-δ phase transition of FAPbI₃. Prevalent iodine vacancies and interstitials can significantly expedite the structural transition kinetics by inducing robust covalency during transition states. Extrinsically, the detrimental roles of atmospheric moisture and oxygen in degrading the FAPbI₃ perovskite phase are also rationalized. Significantly, we discover the compositional design principles by categorizing that A-site engineering primarily governs thermodynamics,

SUBMITTER: Liang Y 

PROVIDER: S-EPMC10894298 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature