Blue light-emitting material having a perovskite-like structure and improved photoluminescent quantum yield, and method of preparing same

A method of preparing a blue light-emitting material, the method comprising:

• mixing a halide of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, or a combination thereof, and a halide of Sc, Y, Al, Gd, Lu, or a combination thereof to form a mixture;
• heating the mixture at a temperature of from 500° C. to 600° C. under a strongly reducing atmosphere to form a heated material;
• and
• sintering the heated material at a temperature of from 600° C. to 700° C. under a strongly reducing atmosphere to form a sintered material.

A blue light-emitting material represented by Chemical Formula 1,

• wherein the blue light-emitting material is prepared by mixing a halide of Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, or a combination thereof, and a halide of Sc, Y, Al, Gd, Lu, or a combination thereof to form a mixture;
• heating the mixture together with magnesium powder, titanium powder, or a combination thereof to form a heated material;
• and sintering the heated material at a temperature higher than that of the heating, and
• wherein the blue light-emitting material has an emission peak wavelength of 380 nanometers to 500 nanometers, upon being excited by an excitation source having a wavelength range of 250 nanometers to 400 nanometers, a full width at half maximum of the emission peak wavelength of less than 30 nm, a photoluminescent quantum yield (PLQY) of 80% or more, and an average luminescence lifetime of 80 nanoseconds or more:
• wherein in Chemical Formula 1,
• A comprises Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, or a combination thereof,
• M comprises Sc, Y, Al, Gd, Lu, or a combination thereof, and
• X comprises O, F, Cl, Br, I, or a combination thereof.