The present invention relates to metal halide colloidal nanoparticles represented by a following Chemical Formula 1 and a method for producing the same:

A.sub.3MX.sub.6  [Chemical Formula 1] wherein in the Chemical Formula 1, A is an alkali metal element, M is a rare-earth metal element, and X is a halogen element.

The embodiments provide a radiation detection material emitting fluorescence with high intensity and short lifetime, and also provide a radiation detection device. The polycrystalline radiation detection material of the embodiment is represented by the following formula (1)
TlM.sub.1-x-yR.sub.xX.sub.3-z  (1).
In the formula, M is at least one metal element selected form the group consisting of Ca, Sr, Ba and Mg; R is at least one luminescence center element selected form the group consisting of Ce, Pr, Yb and Nd; X is at least one halogen element selected form the group consisting of Cl, Br and F; and x, y and z are numbers satisfying the conditions of 0≤x≤0.5, −0.1≤y≤0.1, and −0.5≤z≤1, respectively.

Eutectic lithium chloride-cerium chloride (LiCl—CeCl.sub.3) compositions are described. An exemplary eutectic composition has about 75 mole % LiCl and about 25 mole % CeCl.sub.3. The eutectic compositions can have optical and/or scintillation properties. Also described are methods of preparing the eutectic compositions as well as methods of using radiation detectors including the eutectic compositions in the detection of radiation, including thermal neutrons.

The embodiments provide a radiation detection material emitting fluorescence with high intensity and short lifetime, and also provide a radiation detection device. The polycrystalline radiation detection material of the embodiment is represented by the following formula (1)

TlM.sub.1-x-yR.sub.xX.sub.3-z  (1).

In the formula, M is at least one metal element selected form the group consisting of Ca, Sr, Ba and Mg; R is at least one luminescence center element selected form the group consisting of Ce, Pr, Yb and Nd; X is at least one halogen element selected form the group consisting of Cl, Br and F; and x, y and z are numbers satisfying the conditions of 0≤x≤0.5, −0.1≤y≤0.1, and −0.5≤z≤1, respectively.

A method for preparing inorganic halogenated lead perovskite quantum dots and a display device are provided. The method includes: a first coordination solution preparing step, a cerium oleate solution preparing step, a centrifugal separation step, a second coordination solution preparing step, a first ion exchange step, and a second ion exchange step. The present invention also provides a display device including a quantum dot layer, wherein luminescent quantum dots of the quantum dot layer are inorganic halogenated lead cesium perovskite quantum dots of the present invention.

Lanthanide double perovskite nanocrystals are described. The nanocrystals display high energy luminescence, making them useful in a variety of light-emitting materials and devices. Methods of preparing the lanthanide double perovskite nanocrystals using a hot injection method are also described.

A stabilized scintillator includes a compound corresponding to formula (2) or (3), or activated derivatives thereof:
A.sub.2BB.sub.xB.sub.yX.sub.6(2)
A.sub.2BBX.sub.xX.sub.y(3)
wherein A and B are monovalent cations, B is a trivalent cation, X is a halogen, x and y are molar percentages, x+y=1; B is an aliovalent exchange cation that has a different valence than B, X is an aliovalent exchange anion that has a different valence than X. A method of preparing the stabilized scintillator is also disclosed.

Mixed halide scintillation materials of a first general formula A.sub.4B.sub.(1-y)M.sub.yX.sub.6(1-z)X.sub.6z and a second general formula A.sub.(4-y)BM.sub.yX.sub.6(1-z)X.sub.6z are disclosed. In the general formulas, A is an alkali metal, B is an alkaline earth metal, and X and X are two different halogen atoms. Scintillation materials of the first general formula include a divalent external activator M such as Eu.sup.2+ or Yb.sup.2+ or a trivalent external activator M such as Ce.sup.3+. Scintillation materials of the second general formula include a monovalent external activator M such as In.sup.+, Na.sup.+, or Tl.sup.+ or a trivalent external activator such as Ce.sup.3+.

The present invention relates to metal halide colloidal nanoparticles represented by a following Chemical Formula 1 and a method for producing the same:
A.sub.3MX.sub.6[Chemical Formula 1] wherein in the Chemical Formula 1, A is an alkali metal element, M is a rare-earth metal element, and X is a halogen element.

The present invention aims at providing a scintillator for high temperature environments which has satisfactory light emission characteristics under high temperature environments; and a method for measuring radiation under high temperature environments. The scintillator for high temperature environments comprises a colquiriite-type crystal represented by the chemical formula LiM.sup.1M.sup.2X.sub.6 (where M.sup.1 is at least one alkaline earth metal element selected from Mg, Ca, Sr and Ba, M.sup.2 is at least one metal element selected from Al, Ga and Sc, and X is at least one halogen element selected from F, Cl, Br and I), for example, typified by LiCaAlF.sub.6, and the crystal optionally containing a lanthanoid element such as Ce or Eu. The method for measuring radiation under high temperature environments uses the scintillator.