Organic solvent-free lyophilization assisted recrystallization synthesis of high-purity green emissive Cs3MnX5 (X=I, Br)

Abstract Light-emitting materials such as perovskite, quantum dots, and commercialized phosphors have attracted attention from the world because of their excellent optical properties. However, these materials require various organic solvents, high temperature, high pressure, and gas in the synthesis process. In the present study, the inorganic metal halide (IMH) was synthesized using the lyophilization assisted recrystallization (LARC) method. In addition, the material does not contain toxic metal such as lead and cadmium, and confirmed green luminescence arose from d5 configuration with the d-d transition of halogen anion coordinated manganese complex in the new structure Cs3MnX5 (X = I, Br). It exhibited a luminescence characteristic with a narrow band emission (full width at half maximum (FWHM) = 42 nm and 39 nm) at the center wavelength of 540 and 520 nm, and high photoluminescence quantum yield (PLQY) of 78.5% and 74.9% under the blue excitation, respectively. This material is expected to serve as a luminescent material that can replace commercial green phosphors.