# US 10,770,627 B2 · Wavelength converting material for a light emitting device

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- Number: US 10,770,627 B2
- Document ID: US10770627B2
- Status: Granted
- Kind: B2
- Application number: 16/342,491
- Filed: 2018-09-12
- Published: 2020-07-16
- Granted: 2020-09-08
- Earliest claimed: 2017-09-28
- Assignees: Lumileds Holding B.V.
- Applicants: Lumileds Holding B.V.
- Inventors: Peter Josef Schmidt; Rob Engelen; Thomas Diederich
- Web page: https://patentgrep.com/patent/US10770627B2

## CPC

- H10H 20/8512: {Wavelength conversion materials}
- H10H 20/8513: {having two or more wavelength conversion materials}
- C09K 11/7708: {Vanadates; Chromates; Molybdates; Tungstates}
- C09K 11/77744: {Aluminosilicates}
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

Embodiments of the invention include an infrared-emitting phosphor comprising (La,Gd)3Ga5−x−yAlxSiO14:Cry, where 0≤x≤1 and 0.02≤y≤0.08. In some embodiments, the infrared-emitting phosphor is a calcium gallogermanate material. In some embodiments, the infrared-emitting phosphor is used with a second infrared-emitting phosphor. The second infrared-emitting phosphor is one or more chromium doped garnets of composition Gd3−x1Sc2−x2−yLux1+x2Ga3O12:Cry, where 0.02≤x1≤0.25, 0.05≤x2≤0.3 and 0.04≤y≤0.12.

## Claims

### Claim 1

A luminescent material, comprising:
a host lattice crystallizing in a trigonal calcium gallogermanate structure type; and
dopants disposed in the host lattice, the dopants comprising:
trivalent chromium; and
tetravalent chromium in a concentration that is less than 1% of a total concentration of all chromium in the luminescent material.

### Claim 2 (depends on 1)

The luminescent material of claim 1, wherein the host lattice comprises a tetravalent cation with an effective atomic radius at least 10% smaller than an effective ionic radius of Cr(IV).

### Claim 3 (depends on 1)

The luminescent material of claim 1, wherein the luminescent material is RE3Ga5−x−yAxSiO14:Cry (RE=La, Nd, Gd, Yb, Tm; A=Al, Sc), where 0≤x≤1 and 0.005≤y≤0.1.

### Claim 4 (depends on 1)

The luminescent material of claim 1, wherein the host lattice is La3Ga5−xSiO14.

### Claim 5 (depends on 1)

The luminescent material of claim 1, wherein the luminescent material emits light within a 700-1100 nm range.

### Claim 6 (depends on 1)

The luminescent material of claim 1, wherein the luminescent material is (La,Gd)3Ga5−x−yAlxSiO14:Cry, where 0≤x≤1 and 0.02≤y≤0.08.

### Claim 7 (depends on 6)

The luminescent material of claim 6, wherein the luminescent material is excited by blue or red light.

### Claim 8 (depends on 1)

The luminescent material of claim 1 wherein the luminescent material has a full width at half maximum between 1700 cm−1 and 4000 cm−1.

### Claim 9 (depends on 6)

The luminescent material of claim 6, wherein the band gap of the luminescent material is at least 4.8 eV.

### Claim 10 (depends on 1)

The luminescent material of claim 1 wherein the luminescent material is La2.98Gd0.02Ga4.76Al0.2SiO14:Cr0.04.

### Claim 11 (depends on 6)

The luminescent material of claim 6 wherein the luminescent material has a full width at half maximum between 1700 cm−1 and 4000 cm−1.

### Claim 12 (depends on 6)

The luminescent material of claim 6, wherein the luminescent material is La2.98Gd0.02Ga4.76Al0.2SiO14:Cr0.04.

### Claim 13 (depends on 1)

A device comprising:
a light source;
the luminescent material of claim 1; and
a second luminescent material crystallizing in the cubic garnet structure type.

### Claim 14 (depends on 13)

The device of claim 13 wherein the first luminescent material is RE3Ga5−x−yAxSiO14:Cry (RE=La, Nd, Gd, Yb, Tm; A=Al, Sc), where 0≤x≤1 and 0.005≤y≤0.1.

### Claim 15 (depends on 13)

The device of claim 13, wherein the second luminescent material is:
Gd3−xRExSc2−y−zLnyGa3−wAlwO12:Crz (Ln=Lu, Y, Yb, Tm; RE=La, Nd), where 0≤x≤3; 0≤y≤1.5; 0≤z≤0.3; and 0≤w≤2;
AAEM1−xF6:Crx (A=Li, Cu; AE=Sr, Ca; M=Al, Ga, Sc) where 0.005≤x≤0.2; or
A2−x(WO4)3:Crx (A=Al, Ga, Sc, Lu, Yb) where 0.003≤x≤0.5.

### Claim 16 (depends on 13)

The device of claim 13, wherein:
the first luminescent material is (La,Gd)3Ga5−x−yAlxSiO14:Cry, where 0≤x≤1 and 0.02≤y≤0.08; and
the second luminescent material is Gd3−x1Sc2−x2−yLux1+x2Ga3O12:Cry, where 0.02≤x1≤0.25, 0.05≤x2≤0.3 and 0.04≤y≤0.12.

### Claim 17 (depends on 13)

The device of claim 13, wherein:
the first luminescent material is La2.98Gd0.02Ga4.76Al0.2SiO14:Cr0.04; and
the second luminescent material is Gd2.85Sc1.75Lu0.3Ga3O12:Cr0.1.