Direct Hot-Injection Synthesis of Mn-Doped CsPbBr₃ Nanocrystals

Abstract

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[Pb1–x Mn x ]­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[Pb1–x Mn x ]­Br4 and Mn-doped CsPbBr3 nanocrystals, suggesting the possible role of L2[Pb1–x Mn x ]­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.

Lead‐Free Semiconductors: Soft Chemistry, Dimensionality Control, and Manganese‐Doping of Germanium Halide Perovskites

“…In all cases, the actual Mn 2+ incorporation is lower than the synthetic Mn 2+ loading, which indicates that Ge 2+ is preferentially incorporated into the CsGeX 3 lattice. This is consistent with previous reports on Mn 2+ ‐doped CsPbX 3 nanocrystals, whose fast nucleation kinetics reduces Mn 2+ incorporation ,,,. Interestingly, the chemical yield systematically decreases with increasing synthetic Mn 2+ loading, likely because the parent CsMnX 3 compound is too soluble in water and thus fails to completely precipitate (see S.…”

“…Recently, significant research focused on doping metal halide perovskites with transition or main group metals . Doping with up to 46% Mn 2+ is currently possible, leading to modified magnetic and optical properties . Mn 2+ ‐doping enhances stability, increases quantum yield to 60%, and results in long exciton lifetimes ,.…”

“…[56][57][58] Doping with up to 46% Mn 2 + is currently possible, [59] leading to modified magnetic and optical properties. [60][61][62][63][64] Mn 2 + -doping enhances stability, [65][66][67] increases quantum yield to 60%, [68] and results in long exciton lifetimes. [69,70] These enhanced properties are useful for LEDs [67,71] and solar cell downconverters.…”

Low‐dimensional metal halide perovskites and related optoelectronic applications

“…In addition to ligand‐assisted precipitation, hot‐injection is another efficient method to synthesize monodisperse perovskite nanocrystals . Inorganic CsPbX 3 nanocrystals were achieved (Figure A‐C) by the injection of cesium oleate into a mixed solution of PbX 2 , oleic acid, and oleylamine in a high boiling solvent (octadecene) at 140°C‐200°C .…”

Silver nanoparticles enhanced luminescence and stability of CsPbBr3 perovskite quantum dots in borosilicate glass

“…There have been many routes to prepare this type of semiconductor material, including thermal injection, ligand‐assisted supersaturation recrystallization, a microwave‐assisted method, and an ion exchange method . Although perovskite quantum dots possess excellent optical properties, their poor stability limits their practical application.…”