Shape-Dependent Kinetics of Halide Vacancy Filling in Organolead Halide Perovskites

Halide perovskites show high photoluminescence quantum yields and tunable bandgap. While perovskites' optical properties significantly degrade due to the ionic and electronic defects, a correlation among their structure, size, defects, and degradation rate remains concealed. The authors report the crystal shape- and halide vacancy-dependent stability of methylammonium lead bromide single crystals. The vacancies are filled in the cubic-, plate-, and rod-shaped crystals by the halide-soaking and light-soaking processes. The differences in the stability, photoluminescence intensity, lifetime, and vacancy filling rates in these geometrical shapes derive from their specific surface-to-volume ratios. The shape-dependent vacancy filling helps to correlate the electron microscope images, elemental compositions, and the photoluminescence intensity and lifetime.

Automated summary

This study investigates the stability of methylammonium lead bromide single crystals based on crystal shape and halide vacancies, revealing differences in vacancy filling rates in different shapes and emphasizing the correlation between surface-to-volume ratios and stability.,Objective are to correlate the stability behavior of halide perovskites to their specific geometrical shapes and disruption caused by vacancies.