Perovskite-type halides and methods thereof
Metal halide optical materials (e.g., scintillator materials or persistent phosphors) are described. More particularly, the optical materials include codoped perovskite-type halides, wherein the codoping ion is present at a molar ratio of 5000 parts per million (ppm) or less with respect to all cations. For example, the optical material can be a codoped trihalide having the formula ABX 3 where A is one or more alkali metal, B is one or more alkali earth metal, and X is one or more halide that is doped with up to about 10 atomic percent of a dopant ion and codoped with up to about 5000 ppm of one or more isovalent or aliovalent codopant ion, such as a tetravalent ion (e.g., Zr 4+ ), a trivalent ion (e.g., Sc 3+ , Y 3+ , Gd 3+ , or La 3+ ion) or a divalent ion (e.g., Mg 2+ ). The codoped material can have modified afterglow compared to a noncodoped material.
1. An optical material comprising a composition of Formula (I):
[(A 1-x M x )(B 1-y M′ y )] 1-z D z X 3 (I),
wherein:
0≤x≤0.1 and 0≤y≤0.1, subject to the proviso that at least one of x and y is at least 0.0001;
0.0001≤z≤0.1;
A is Li, Na, K, Rb, Cs, or any combination thereof;
B is Be, Mg, Ca, Sr, Ba, or any combination thereof;
M is In, TI, or a combination thereof;
M′ is Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb, Bi, Sb, or any combination thereof;
D is at least one type of monovalent, divalent, trivalent, or tetravalent cation; and
X is F, Cl, Br, I, or any combination thereof.
2. The optical material of claim 1 , wherein 0.0001≤z≤0.005.
3. The optical material of claim 1 , wherein D is a trivalent cation or mixture thereof.
4. The optical material of claim 1 , wherein D is selected from the group consisting of Mg, Sc, Y, Gd, La, Zr, and combinations thereof.
5. The optical material of claim 1 , wherein the optical material comprises a composition of Formula (II):
(AB 1-y M′ y ) 1-z D z X 3 (II),
wherein:
0.0001≤y≤0.1;
0.0001≤z≤0.1;
A is Li, Na, K, Rb, Cs, or any combination thereof;
B is Be, Mg, Ca, Sr, Ba, or any combination thereof;
M′ is Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb, Bi, Sb, or any combination thereof;
D is at least one type of monovalent, divalent, trivalent, or tetravalent cation; and
X is F, Cl, Br, I or any combination thereof.
6. The optical material of claim 5 , wherein 0.01≤y≤0.05.
7. The optical material of claim 5 , wherein 0.001≤z≤0.005.
8. The optical material of claim 5 , wherein A is K.
9. The optical material of claim 5 , wherein B is Ca, Sr, or a combination thereof.
10. The optical material of claim 5 , wherein M′ is Eu.
11. The optical material of claim 5 , wherein y is 0.03.
12. The optical material of claim 5 , wherein D is a trivalent cation or a combination thereof.
13. The optical material of claim 5 , wherein D is Mg, Sc, Y, Gd, La, Zr, or a combination thereof.
14. The optical material of claim 13 , wherein D is Sc.
15. The optical material of claim 13 , wherein D is Mg or Zr.
16. The optical material of claim 5 , wherein X is I.
17. The optical material of claim 1 , wherein the optical material comprises a composition of Formula (III):
(KCa 1-y Eu y ) 1-z D z X 3 (III),
wherein:
0.01≤y≤0.1;
0.0001≤z≤0.005;
D is Mg, Zr, one or more trivalent cations, or a combination thereof; and
X is Cl, Br, I or any combination thereof.
18. The optical material of claim 17 , wherein y is 0.03.
19. The optical material of claim 17 , wherein 0.001≤z≤0.005.
20. The optical material of claim 17 , wherein X is I.
21. The optical material of claim 17 , wherein D is Mg, Sc, Y, Gd, La, Zr, or any combination thereof.
22. The optical material of claim 21 , wherein D is Sc, Zr, or Mg.
23. The optical material of claim 1 , wherein the optical material has reduced afterglow compared to an optical material where D is absent.
24. The optical material of claim 1 , wherein the optical material has increased afterglow compared to an optical material where D is absent.
25. The optical material of claim 1 , wherein the optical material is a single crystal material.
26. A radiation detector comprising a photon detector and an optical material of claim 1 .
27. The radiation detector of claim 26 , wherein the detector is a medical diagnostic device, a device for oil exploration, or a device for container or baggage scanning.
28. A method of detecting gamma rays, X-rays, cosmic rays and/or particles having an energy of 1 keV or greater, the method comprising using the radiation detector of claim 26 .
29. A method of preparing an optical material of claim 1 , wherein the method comprises heating a mixture of raw materials above their respective melting temperatures.
30. The method of claim 29 , wherein the method comprises:
(a) providing a mixture of raw materials, wherein the raw materials are provided in a stoichiometric ratio according to Formula (I):
[(A 1-x M x )(B 1-y M′ y )] 1-z D z X 3 (I),
wherein:
0≤x≤0.1 and 0≤y≤0.1, subject to the proviso that at least one of x and y is at least 0.0001;
0.0001≤z≤0.1;
A is Li, Na, K, Rb, Cs, or any combination thereof;
B is Be, Mg, Ca, Sr, Ba, or any combination thereof;
M is In, TI, or a combination thereof;
M′ is Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb, Bi, Sb, or any combination thereof;
D is at least one type of monovalent, divalent, trivalent, or tetravalent cation; and
X is F, Cl, Br, I, or any combination thereof;
(b) sealing the mixture in a sealed container;
(c) heating the mixture to about 20° C. above the melting point of the raw material having the highest melting point for a period of time;
(d) cooling the mixture to about room temperature; and
(e) optionally repeating steps (c) and (d).