Systematic Microwave-Assisted Postsynthesis of Mn-Doped Cesium Lead Halide Perovskites with Improved Color-Tunable...

The metal doping at the Pb²⁺ position provides improved luminescence performance for the cesium lead halide perovskites, and their fabrication methods assisted by microwave have attracted considerable attention due to the advantages of fast heating and low energy consumption. However, the postsynthetic doping strategy of the metal-doped perovskites driven by microwave heating still lacks systematic research. In this study, the assembly of CsPbBr₃/CsPb₂Br₅ with a strong fluorescence peak at 523 nm is used as the CsPbBr₃ precursor, and through the optimization of the postsynthetic conditions such as reaction temperatures, Mn²⁺/Pb²⁺ feeding ratios, and Mn²⁺ sources, the optimum Mn²⁺-doped product (CsPb(Cl/Br)₃:Mn) is achieved. The exciton fluorescence peak of CsPb(Cl/Br)₃:Mn is blueshifted to 437 nm, and an obvious fluorescence peak attributing to the doped Mn²⁺ ions at 597 nm is obtained. Both the CsPbBr₃ precursor and CsPb(Cl/Br)₃:Mn have high PLQY and stability because there are CsPb₂Br₅ microcubic crystals to well disperse and embed the CsPbBr₃ nanocrystals (NCs) in the precursor, and after Mn²⁺-doping, this structure is maintained to form CsPb(Cl/Br)₃:Mn NCs on the surface of their microcrystals. The exploration of preparation parameters in the microwave-assisted method provides insights into the enhanced color-tunable luminescence of the metal-doped perovskite materials.