Fig. 1. Perovskite crystal structure of ABX₃ class^［5］

Fig. 2. Schematic of the QDs growth^［6］

Fig. 3. （a）Schematic of heat injection method；（b）Precursor solution in ligand-assisted precipitation method；（c）Reaction process of precursor solution；（d）CsPbBr₃ solution prepared^［7］.

Fig. 4. Schematic diagram of the acid etching process^［11］

Fig. 5. Crystal structure（a）and reflectance（b）of Cs_1-xRb_xPbBr₃^［15］

Fig. 6. （a）Structural diagram of the three-dimensional perovskite from the <100> crystal surface^［19］；（b）Crystal structure of the layered perovskite in the RP and DJ phase（n=3）^［19］；（c）Crystal structure of the layered perovskite in the ACI phase（n=1，2，3）^［20］.

Fig. 7. Schematic diagram of quasi-2D perovskite film and quasi-2D perovskite film at PVDF sealing end^［27］

Fig. 8. （a）Schematic diagram of some of the cations in CsPbBr₃ nanocrystals exchanged by other divalent cations（Sn²⁺，Cd²⁺ and Zn²⁺）and photographs of the colloid suspension illuminated with UV light^［28］；（b）PL spectra of Nd³⁺ doped CsPbBr₃ nanocrystals with different concentrations^［31］.