Fig. 6. Stable defect dynamics in PbI₂.

a–d Time-lapse ADF-STEM images taken after every 2 min. The red and blue boxes show the two different orientations of the substitutional defect, which is rather stable under the electron beam exposure. e ADF-STEM image of a defect with lead in the center and surrounded by five other iodide atoms. f Atomic model that shows the atomic model of the corresponding experimental result. g Multislice image simulations based on the atomic model in f, schematically illustrating the lower intensity of the single iodide atoms surrounding the lead, which agrees with the experimental data in e. m, n Line profile taken across the lead and iodide atoms across the yellow annotated regions in the experimental data k and multislice simulated image in l. The red arrow shows unresolved iodide peaks around the lead. o, p Line profile taken across the lead and iodide atoms across the blue annotated region in k and l, respectively. The red arrow shows unresolved iodide peaks around the lead. j, h ADF-STEM image of the opposite orientated substitutional defect. i Atomic model that shows the atomic model of the corresponding experimental result. j Multislice image simulations based on the atomic model in i, schematically illustrating the lower intensity of the single iodide atoms surrounding the lead, which agrees with the experimental data in h. s, t Line profile taken across the lead and iodide atoms across the yellow annotated regions in the experimental data q and multislice simulated image in r. The red arrow shows unresolved iodide peaks around the lead. u, v Line profile taken across the lead and iodide atoms across the blue annotated region in q and r, respectively. The red arrow shows unresolved iodide peaks around the lead. w Annotated image of e. x Distance between the different atoms shown in the annotated region in w. Scale bars in a–d correspond to 2 nm, whereas in the rest of the images correspond to 1 nm.