Light-emitting device

Patent metadata

Field	Value
Publication number	US-10903401-B2
Application number	US-201916296803-A
Country	US
Kind code	B2
Filing date	Mar 8, 2019
Priority date	Jan 13, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

Provided is a light-emitting device including a light-emitting element having a peak emission wavelength in a range of from 400 nm to 470 nm, and a fluorescent member including a first fluorescent material including an aluminate that contains Mg, Mn, and at least one alkali earth metal selected from the group consisting of Ba, Sr, and Ca, a second fluorescent material having a different composition from the first fluorescent material, and a third fluorescent material. The first, second and third fluorescent materials have a peak emission wavelength in a range of from 510 nm to 525 nm, from 510 nm to 550 nm, and from 620 nm to 670 nm, respectively.

First claim

What is claimed is:

1. A light-emitting device comprising:
a light-emitting element having a peak emission wavelength in a range of from 400 nm to 470 nm; and
a fluorescent member including
a first fluorescent material containing an aluminate that contains Mg, Mn, and at least one alkali earth metal selected from the group consisting of Ba, Sr, and Ca, and has a peak emission wavelength in a range of from 510 nm to 525 nm,
a second fluorescent material having a different composition from the first fluorescent material, and a peak emission wavelength in a range of from 510 nm to 550 nm, and
a third fluorescent material having a peak emission wavelength in a range of from 620 nm to 670 nm,

wherein a ratio of a half bandwidth of the second fluorescent material to a half bandwidth of the first fluorescent material is 1.1 or more and 2.5 or less.

2. The light-emitting device according to claim 1 , wherein the first fluorescent material has a composition represented by formula (I):
X 1 p Eu t Mg q Mn t Al s O p+t+q+r+1.5s   (I)

wherein X 1 is at least one selected from the group consisting of Ba, Sr, and Ca; and p, q, r, s and t satisfy 0.5≤p≤1, 0≤q≤0.7, 0.2≤r≤0.7, 8.5≤s≤13, 0≤t≤0.5, 0.5≤p+t≤1.2, and 0.2≤q+r≤1.

3. The light-emitting device according to claim 2 , wherein X 1 contains Ba, and p satisfies 0.6≤p≤1 in the formula (I).

4. The light-emitting device according to claim 2 , wherein r satisfies 0.3≤r≤0.6 in the formula (I).

5. The light-emitting device according to claim 1 , wherein the second fluorescent material contains at least one material selected from the group consisting of β sialon fluorescent materials, silicate fluorescent materials, and sulfide fluorescent materials.

6. The light-emitting device according to claim 1 , wherein the second fluorescent material contains at least one selected from the group consisting of fluorescent materials having a composition represented by any of formulas (IIa) to (IId) below:
Si 6-z Al z O z N 8-z :Eu, 0 ≤z≤ 4.2  (IIa)

(Ca,Sr) 8 MgSi 4 O 16 (Cr,F,Br) 2 :Eu  (IIb)

(Sr,Ca,Ba)Ga 2 S 4 :Eu  (IIc)

(Ba,Sr,Ca) 2 SiO 4 :Eu  (IId).

7. The light-emitting device according to claim 6 , wherein the second fluorescent material has a composition represented by the formula (IIa), and has a content ratio of less than 10% by weight relative to a total amount of the first fluorescent material and the second fluorescent material contained in the fluorescent member.

8. The light-emitting device according to claim 6 , wherein the second fluorescent material has a composition represented by the formula (IIb) or (IId), and the second fluorescent material has a content ratio of less than 1% by weight relative to a total amount of the first fluorescent material and the second fluorescent material contained in the fluorescent member.

9. The light-emitting device according to claim 6 , wherein the second fluorescent material has a composition represented by the formula (IIc), and the second fluorescent material has a content ratio of less than 0.5% by weight relative to a total amount of the first fluorescent material and the second fluorescent material contained in the fluorescent member.

10. The light-emitting device according to claim 1 , wherein the third fluorescent material contains at least one material selected from the group consisting of fluoride fluorescent materials, magnesium fluoro-germanate fluorescent materials, nitride fluorescent materials, and sulfide fluorescent materials.

11. The light-emitting device according to claim 1 , wherein the third fluorescent material contains at least one material selected from the group consisting of fluorescent materials having a composition represented by any one of formulas (IIIa) to (IIIe) below:
K 2 (Si,Ge,Ti)F 6 :Mn  (IIIa),

3.5MgO.0.5MgF 2 .GeO 2 :Mn  (IIIb)

(Sr,Ca)AlSiN 3 :Eu  (IIIc)

(Sr,Ca)LiAl 3 N 4 :Eu  (IIId)

(Ca,Sr)S:Eu  (IIIe)

12. The light-emitting device according to claim 1 , wherein the second fluorescent material has a longer peak emission wavelength than the first fluorescent material.

13. The light-emitting device according to claim 1 , emitting light in a range of x from 0.22 to 0.34 and y from 0.16 to 0.34 in CIE 1931 xy chromaticity coordinates.

Assignees

• Nichia Corp

Inventors

• Hosokawa Shoji
• Nishimata Kazuya
• Yoshida Tomokazu

Classifications

• C09K11/77348

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• C09K11/7734

  Aluminates · CPC title

• C09K11/77342

  Silicates · CPC title

• H10H20/8506

  Containers · CPC title

• H10H20/882

  Scattering means (H10H20/82 takes precedence) · CPC title