How Methylammonium Iodide Reactant Size Affects Morphology and Defect Properties of Mechanochemically Synthesized MAPbI3 Powder

Here, we investigate in detail the impact of the size of the methylammonium iodide (MAI) reactants in the mechanochemical powder synthesis of the halide perovskite methylammonium lead iodide (MAPbI(3)). Morphology and structural characterizations by scanning electron microscopy and X-ray diffraction reveal that with increasing MAI reactant size, the particle size of the perovskite powder increases, while its defect density decreases, as suggested by nuclear quadrupole resonance spectroscopy and photoluminescence investigations. The reason for this behavior seems to be associated to the sensitive influence of the MAI size on the time durations of MAPbI(3) synthesis and delayed MAPbI(3) crushing stage during ball milling. Thus, our results emphasize the high importance the reactant properties have on the mechanochemical synthesis of halide perovskites and will contribute to enhance the reproducibility and control of the fabrication of halide perovskites in powder form.

Automated summary

In this study, we investigated the impact of the size of methylammonium iodide (MAI) reactants on the mechanochemical powder synthesis of halide perovskite methylammonium lead iodide (MAPbI(3)). Our results showed that the particle size of the perovskite powder increased and its defect density decreased with increasing MAI reactant size. This behavior seemed to be associated with the influence of MAI size on the time durations of MAPbI(3) synthesis and the crushing stage during ball milling.