Fig. 1. HAADF-STEM images demonstrating the Pb nanoparticle formation on CsPbBr₃ nanocrystals induced by 200 keV electron irradiation at increasing temperature: (a)–(c) 3 nm thick nanosheet and (d)–(f) nanocubes of edge size of 20 nm. (g) HRTEM image of CsPbBr₃ nanosheet showing the atomic details of the Pb nanoparticles.

Fig. 2. Crystal model and HAADF-STEM images at different temperatures under 200 keV electron irradiation for nanocrystals of (a)–(d) Cs₄PbBr₆ (Cs, Br, and Pb atoms as big cyan spheres, small green and blue spheres, respectively, PbBr₆ octahedra are shaded in blue), (e)–(h) Cs₃CoCl₅ (Cs atoms in cyan, Cl atoms in green, Co atoms in blue, CoCl₆ octahedra in blue), (i)–(k) Cs₃Bi₂I₉ (Cs atoms in cyan, I atoms in green, Bi atoms in blue, and BiI₆ octahedra in blue).

Fig. 3. HRTEM images of (a), (b) Cs₃CoCl₅ nanowires showing the formation of metallic Co nanoparticles and (c), (d) Cs₃Bi₂I₉ naoncrystals demonstrating the creation of Bi nanoparticles.