Direct Hot-Injection Synthesis of Mn-Doped CsPbBr₃ Nanocrystals

We report the direct hot-injection synthesis of Mn-doped cesium lead bromide (CsPbBr₃) perovskite nanocrystals. In contrast to Mn-doped CsPbCl₃ nanocrystals, where doping of Mn under typical hot-injection synthesis condition has been relatively straightforward, extending the same approach to CsPbBr₃ has been very difficult. Here, we achieved the synthesis of Mn-doped CsPbBr₃ nanocrystals via the formation of an intermediate structure (L₂[Pb_1–<i>x</i>Mn_<i>x</i>]­Br₄, L = ligand) before the hot-injection of the Cs precursor, which contains the same Mn–Br coordination present in Mn-doped CsPbBr₃ nanocrystals. A strong correlation was observed between the Mn luminescence intensities of L₂[Pb_1–<i>x</i>Mn_<i>x</i>]­Br₄ and Mn-doped CsPbBr₃ nanocrystals, suggesting the possible role of L₂[Pb_1–<i>x</i>Mn_<i>x</i>]­Br₄ as the structural precursor to Mn-doped CsPbBr₃ nanocrystals. The successful Mn doping in CsPbBr₃ nanocrystal host, which has significantly better optical characteristics than CsPbCl₃ nanocrystals, will expand the range of useful properties of Mn-doped cesium lead halide perovskite nanocrystals resulting from the coupling of exciton and Mn