Blue-emitting phosphors and methods of use thereof
Provided herein are phosphors of the general molecular formula: (A 2-2x Eu x )(Mg 1-y Ca y )PO 4 F wherein the variables are as defined herein. Methods of producing the phosphors are also provided. In some aspects, the present disclosure provides light-emitting devices comprising these phosphors.
1. A phosphor of the general molecular formula:
(A 2-2x Eu x )MgPO 4 F,
wherein:
A is one or more alkali metal;
0<x≤0.25.
2. The phosphor of claim 1 , wherein A is sodium (I).
3. The phosphor of claim 1 , wherein 0<x≤0.1.
4. The phosphor of claim 1 , wherein x is 0.005, 0.01, 0.02, 0.04, or 0.06.
5. The phosphor of claim 1 , further defined as Na 1.92 Eu 0.04 MgPO 4 F.
6. The phosphor of claim 1 , wherein the phosphor has an excitation spectrum peak at an excitation wavelength from about 260 nm to about 450 nm.
7. The phosphor of claim 1 , wherein the phosphor has an emission spectrum peak at an emission wavelength from about 400 nm to about 500 nm.
8. The phosphor of claim 1 , wherein the emission spectrum peak has a full width at half-maximum (FWHM) of from about 50 nm to about 100 nm.
9. A method for producing a phosphor of claim 1 , wherein the method comprises:
a) mixing starting materials of the phosphor to produce a first reaction mixture, wherein the starting materials of the phosphor comprise one or more alkali metal sources, a magnesium source, a phosphate source, a fluoride source, and a europium source; and
b) heating the first reaction mixture to a first temperature to produce the phosphor, wherein the method comprises a single heating step.
10. The method of claim 9 , wherein the alkali metal source is a sodium source.
11. The method of claim 9 , wherein the phosphate source is a phosphate salt.
12. The method of claim 9 , wherein the europium source is a europium salt or a europium oxide.
13. The method of claim 9 , wherein the first temperature is from about 725° C. to 925° C.
14. The method of claim 9 , wherein mixing is performed in air and heating is performed in a reducing atmosphere.
15. The method of claim 14 , wherein the reducing atmosphere further comprises a diluent gas.
16. A light-emitting device comprising:
a) an excitation light source that emits primary light; and
b) a phosphor of claim 1 , wherein the phosphor is a blue-emitting phosphor.
17. The light-emitting device of claim 16 , wherein the excitation light source is a semiconductor light source.
18. The light-emitting device of claim 16 , wherein the primary light has a wavelength from about 350 nm to about 450 nm.
19. The light-emitting device of claim 16 , wherein the light-emitting device further comprises a green-emitting phosphor, a red-emitting phosphor, or a combination thereof.