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 (L-2[Pb1-xMnx]Br-4, 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 L-2[Pb1-xMnx]Br-4 and Mn-doped CsPbBr3 nanocrystals, suggesting the possible role of L-2[Pb1-xMnx]Br-4 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.