A color conversion element and a display device including the same are provided. The color conversion element includes: a base substrate in which a first region and a second region are defined; a color conversion layer on the base substrate, in the first region, and including color conversion particles configured to convert a wavelength of incident light; and a color light transmitting layer on the base substrate and in the second region; wherein each of the color conversion particles includes a compound represented by Formula 1 (AmBnXl - - - (1)), where, in Formula 1, A is Cs, Rb, or an alloy thereof; B is at least one of Cu, Sb, Ge, Sn, and Bi, or an alloy thereof; m, n, and I are each an integer of 1 to 9; and X is at least one of F, Cl, Br, and I, or a mixture thereof.

A scintillation crystal can include a cesium halide that is co-doped with thallium and another element. In an embodiment, the scintillation crystal can include CsX:Tl, Me, where X represents a halogen, and Me represents a Group 5A element. In a particular embodiment, the scintillation crystal may have a cesium iodide host material, a first dopant including a thallium cation, and a second dopant including an antimony cation.

A method of producing perovskite nanocrystalline particles using a liquid crystal includes a first operation for preparing a mixed solution including a first precursor compound, a second precursor compound, and a first solvent. a second operation for preparing a precursor solution by adding an organic ligand to the prepared mixed solution, a third operation for performing crystallization treatment after adding the prepared precursor solution to a reactor containing a liquid crystal, and a fourth operation for separating the perovskite nanocrystalline particles from the crystallized solution through a centrifugal separator.

A semiconductor nanocrystal particle represented by Chemical Formula 1 and having a full width at half maximum (FWHM) of less than or equal to about 30 nanometers (nm) in the emission wavelength spectrum is provided:
A.sub.xA.sub.(3+x)D.sub.(2+)E.sub.(9+).Chemical Formula 1 In Chemical Formula 1, A is a first metal including Rb, Cs, or a combination thereof, A is an organic substance derived from an ammonium salt, an organic material derived from an organic ligand, or an organic material including a combination thereof, D is a second metal including Sb, Bi, or a combination thereof E is Cl, Br, I, or a combination thereof, 1<x3, 1<<1, 3+x>0, 1<<1, and 1<<1.

A scintillation crystal can include a cesium halide that is co-doped with thallium and another element. In an embodiment, the scintillation crystal can include CsI:Tl, Me, where Me represents co-doped Sb and Bi. In a particular embodiment, the scintillation crystal may have a cesium iodide host material, a first dopant including a thallium, a second dopant including an antimony, and a third dopant including a bismuth.