Granted Patent B2

US 10,533,132 · App. 16/360,861 · Granted Jan 14, 2020

Abstract

Claims (33)

1. A luminescent material comprising AE 1-x Li 2 Be 4 O 6 :Eu x , wherein AE=one or more of Sr, Ba, Ca and 0.002<x≤0.4.

2. The luminescent material of claim 1 wherein the luminescent material emits light having a peak wavelength in the range 440-470 nm.

3. The luminescent material of claim 1 wherein the luminescent material has a spectral widths of full width half maximum (FWHM) of 25-26 nm.

4. The luminescent material of claim 1 wherein the luminescent material has a crystal structure that is isotypic with M 1-x-y-z Z z A a B b C c D d E e N 6-n O n :ES x ,RE y , wherein:

a. M is a divalent element selected from Ca (calcium), Sr (strontium), and Ba (barium);

b. Z is a monovalent element selected from Na (sodium), K (potassium), and Rb (rubidium);

c. A is a monovalent element selected from Li (lithium), and Cu (copper);

d. B is a divalent element selected from Mg (magnesium), Mn (manganese), Zn (zinc), and Cd (cadmium);

e. C is a trivalent element selected from B (boron), Al (aluminum), and Ga (gallium);

f. D is a tetravalent element selected from Si (silicon), Ge (germanium), Ti (titanium), and Hf (hafnium);

g. E is a pentavalent element selected from P (phosphorous), V (vanadium), Nb (niobium), and Ta (tantalum);

h. ES is a divalent rare earth element selected from Eu (europium), Sm (samarium) and Yb (ytterbium);

i. RE is a trivalent rare earth element selected from Ce (cerium), Pr (praseodymium), Nd (neodymium), Sm (samarium), Eu (europium), Gd (gadolinium), Tb (terbium), Dy (dysprosium), Ho (holmium), Er (erbium), and Tm (thulium);

j. 0≤x≤0.2;

k. 0≤y≤0.2;

l. 0<x+y≤0.4;

m. 0≤z<1;

n. x+y+z<1;

o. 0≤n<0.75;

p. a+b=2;

q. c+d+e=4l and

r. a+2b+3c+4d+5e+y−z=16−n.

5. The luminescent material of claim 1 wherein the luminescent material has a lattice structure comprising a single site populated by the Eu(II) activator ions with an eightfold coordination.

6. A device comprising:

a. a semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region, the light emitting layer emitting first light; and

b. the luminescent material according to claim 1 disposed in the path of the first light, wherein the luminescent material absorbs first light and emits second light.

7. The device of claim 6 wherein the first light is blue light.

8. The device of claim 6 wherein the second light is blue light.

9. The device of claim 6 further comprising a green emitting luminescent material and a red emitting luminescent material disposed in the path of the first light.

10. The device of claim 9 wherein the red emitting luminescent material is disposed in the path of the second light.

11. The device of claim 6 wherein the AE 1-x Li 2 Be 4 O 6 :Eu x is a ceramic body.

12. The device of claim 6 wherein the AE 1-x Li 2 Be 4 O 6 :Eu x is a powder disposed in a transparent matrix.

13. The device of claim 12 wherein the transparent matrix is selected from the group consisting of a crystalline material, an alkaline earth halide, and calcium.

Assignments (6)