Light-emitting device

• US 9,112,123 B2
• Filed: 10/28/2011
• Issued: 08/18/2015
• Est. Priority Date: 10/29/2010
• Status: Active Grant

• Current Assignee: National Institute for Materials Science
• Original Assignee: National Institute for Materials Science
• Inventors: Aoki, Kazuo, Watanabe, Makoto, Shimamura, Kiyoshi, Garcia, Villora Encarnacion Antonia
• Primary Examiner(s): Mandala, Victor A
• Application Number:
  US13/882,037
• Publication Number:
  US 20130256730A1
• Time in Patent Office: 1,390 Days
• Field of Search: 257/98, 257/E33.061
• US Class Current: 1/1
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: C30B 15/00 Single-crystal growth by pulling from a melt, e.g. Czochralski method under a protective fluid C30B27/00
• CPC Class Codes: C30B 29/28 with formula A3Me5O12 wherein A is a rare earth metal and Me is Fe, Ga, Sc, Cr, Co or Al, e.g. garnets
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

Abstract

[Problem] To provide a light-emitting device which does not undergo the deterioration in luminous efficiency associated with the long-term use.

[Solution] A light-emitting device (1) comprises a light-emitting element (10) which can emit blue light and a phosphor (2) which is composed of a single kind of single crystal and can emit yellow light upon the irradiation with the light emitted from the light-emitting element (10) which serves as excitation light. Thus, it becomes possible to prevent the deterioration in luminous efficiency associated with the deterioration in a binder or the like compared with a light-emitting device which utilizes multiple kinds of granular phosphors, because any binder for binding phosphors to each other is not required in the light-emitting device (1).

Claims

1. A light-emitting device, comprising:

a light-emitting element to emit a blue light; and

a phosphor comprising a single monocrystal to emit a yellow light by being excited by the light emitted from the light-emitting element,

wherein the phosphor comprises a composition represented by Y_3-x-yL_xM_yAl_5-zN_zO_12-w, where L is Gd or Lu, M is one or more elements selected from the group consisting of Ce, Tb, Eu, Yb, Pr, Tm and Sm, N is Ga or In, 0≦

x<

3, 0.003≦

y≦

0.2, 0≦

z≦

5 and −

0.2≦

w≦

0.2.

2. The light-emitting device according to claim 1, wherein the y of the phosphor is in a range of 0.01≦

y≦

0.2.

3. The light-emitting device according to claim 1, wherein an entirety of the phosphor includes the single monocrystal.

4. A light-emitting device, comprising:

a light-emitting element to emit a blue light; and

a phosphor comprising a single monocrystal to emit a yellow light by being excited by the light emitted from the light-emitting element,

wherein the phosphor comprises a composition represented by Tb_3-x-yGd_xM_y(Sc, Lu)_2-zAl_3-wN_z+wO_12-v, where M is one or more elements selected from the group consisting of Ce, Eu, Yb, Pr, Tm and Sm, N is Ga or In, 0≦

x≦

3, 0≦

y≦

1, 0≦

z≦

2, 0<

w<

3 and −

0.2≦

v≦

0.2.

5. The light-emitting device according to claim 4, wherein the z of the phosphor is in a range of 0.5≦

z≦

2.

6. A light-emitting device, comprising:

a light-emitting element to emit a blue light; and

a phosphor comprising a single monocrystal to emit a yellow light by being excited by the light emitted from the light-emitting element,

wherein the phosphor comprises a composition represented by Tb_3-x-yGd_xM_y(Sc, Lu)_vN_5-vO_12-w, where M is at least one or more elements selected from the group consisting of Ce, Eu, Yb, Pr, Tm, Sm, Nd, Dy, Ho and Er, N is at least one or more elements selected from the group consisting of Ga, In and Al, 0≦

x≦

3, 0≦

y≦

1, 0≦

v≦

5 and −

0.2≦

w<

0.2.

7. The light-emitting device according to claim 6, wherein the v of the phosphor is in a range of 0.5≦

v≦

2.

8. A light-emitting device, comprising:

a light-emitting element to emit a blue light;

a phosphor comprising a single monocrystal to emit a yellow light by being excited by the light emitted from the light-emitting element;

a substrate that supports the light-emitting element;

a main body comprising a reflecting surface disposed around the light-emitting element;

a transparent resin that seals the light-emitting element and the phosphor; and

a wiring electrically connected to electrodes of the light-emitting element,

wherein the wiring is disposed on a upper surface of the substrate, and

wherein the main body and the transparent resin are disposed on an upper surface of the wiring.

9. The light-emitting device according to claim 8, wherein the light-emitting element comprises:

a p-type GaN layer disposed on a upper surface of one of the electrodes of the light-emitting element;

a light-emitting layer disposed on an upper surface of the p-type GaN layer; and

a n-type GaN layer disposed on a upper surface of the light-emitting layer.

10. The light-emitting device according to claim 9, further comprising:

an element substrate comprising sapphire,

wherein the n-type GaN layer is disposed on a first principal surface of the element substrate.

11. The light-emitting device according to claim 10, wherein the light-emitting layer emits the blue light from a carrier injection of the n-type GaN layer and the p-type GaN layer.

12. The light-emitting device according to claim 11, wherein the phosphor is disposed on a second principal surface of the element substrate.

13. The light-emitting device according to claim 12, wherein the single monocrystal includes a crystal which has a size equal to or greater than the second principal surface, and

wherein an intermolecular force joins the phosphor to the element substrate.

14. The light-emitting device according to claim 10, wherein the phosphor is disposed on an entirety of a second principal surface of the element substrate.