Halogen-Hot-Injection Synthesis of Mn-Doped CsPb(Cl/Br)3 Nanocrystals with Blue/Orange Dual-Color Luminescence and High Photoluminescence Quantum Yield

Recently, Mn 2+ -doped CsPb(Cl/Br) 3 perovskite nanocrystals (NCs), showing the advantages of dual-color emissions via exciton-to-dopant energy transfer and reduced usage of toxic Pb 2+ heavy metal ions by nontoxic Mn 2+ substitution, are widely explored. However, photoluminescence quantum yields (PLQYs) for Mn 2+ -doped CsPb(Cl/Br) 3 NCs still need to be further improved. Here, a halogen-hot-injection strategy is developed to prepare Mn:CsPb(Cl 0.6 Br 0.4 ) 3 NCs with the maximal PLQY of 65%. With this method, intense blue narrowband emission from excitonic recombination and orange broadband emission from Mn 2+ 4 T 1 → 6 A 1 transition can be simultaneously achieved. The competitive luminescence between perovskite NCs and Mn 2+ dopants is systematically investigated by controlling the injected halogen types and ratios. As a proof-of-concept experiment, the present Mn 2+ -doped CsPb(Cl/Br) 3 perovskite NCs with highly efficient dual-color emissions are demonstrated to be applicable as color converter in UV-excitable solid-state lighting.