Phosphor, phosphor manufacturing method, and white light emitting device

• US 9,909,058 B2
• Filed: 09/02/2010
• Issued: 03/06/2018
• Est. Priority Date: 09/02/2009
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Yoo, Jae Soo, Kim, Kyung Pil, Lee, Hyun Ju, Kim, Chang Soo
• Primary Examiner(s): Armand, Marc
• Assistant Examiner(s): TANG, SUIAN
• Application Number:
  US12/991,745
• Publication Number:
  US 20110180780A1
• Time in Patent Office: 2,742 Days
• Field of Search: 257 76, 257 89, 257 98, 2573014 F, 257E33061, 257E33034, 313503, 313512
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Provided are a phosphor, a phosphor manufacturing method, and a white light emitting device. The phosphor is represented as a chemical formula of aMO-bAl₂O₃-cSi₃N₄, which uses light having a peak wavelength in a wavelength band of about 350 nm to about 480 nm as an excitation source to emit visible light having a peak wavelength in a wavelength band of about 480 nm to about 680 nm (where M is one kind or two kinds of elements selected from Mg, Ca, Sr, and Ba (0.2≦a/(a+b)≦0.9, 0.05≦b/(b+c)≦0.85, 0.4≦c/(c+a)≦0.9)).

Claims

1. A luminescent material for use with a light emitting device, comprising a composition of one of Sr₃AlSi₂O_9/2N_8/3:

Eu, Sr₂AlSi₃O_7/2N₄;

Eu₂, Sr₂Al₃Si₂O_13/2N_8/3;

Eu₂, or Sr₂Al₃SiO_13/2N_4/3;

Eu₂, wherein at least one peak intensity of light in a wavelength of between about 480 nm to about 680 nm is provided by the luminescent material when excited by light from the light emitting device, and

wherein the composition has a crystal structure in which a portion of a Si—

N bonding of a silicon nitride is substituted for an Al—

N bonding or an Al—

O bonding, and

further wherein the luminescent material of said composition has peak wavelengths in different wavelength bands, and the crystal structure for the luminescent material of said composition having one of the peak wavelengths in the different wavelength bands is different from the crystal structure of the luminescent material of said composition having another one of the peak wavelengths in the different wavelength bands.

2. The luminescent material of claim 1, wherein the light emitting device emits one of UV light and blue light.

3. The luminescent material of claim 1, wherein at least one peak intensity of light in a wavelength of about 350 to about 480 nm is included in the light emitted by the light emitting device.

4. The luminescent material of claim 1, wherein the luminescent material includes a yellow phosphor, a green phosphor and red phosphor,

wherein by weight, an amount of the yellow phosphor is greater than the red phosphor which is less than the green phosphor, and

wherein the amount of yellow phosphor and the green phosphor is different.

5. The luminescent material of claim 4, wherein the green phosphor emits light having a full width at half maximum (FWHM) of about 50 nm to about 100 nm, the yellow phosphor emits light having a FWHM of about 50 nm to about 100 nm or 120 nm or more, and the red phosphor emits light having a FWHM of about 70 nm to about 120 nm.

6. The luminescent material of claim 4, wherein the green phosphor is an oxynitride (ON)-based phosphor or a silicate-based phosphor.

7. The luminescent material of claim 4, wherein the yellow phosphor is a YAG phosphor, a TAG phosphor, or a silicate-based phosphor.

8. The luminescent material of claim 4, wherein the red phosphor is a phosphor having at least one element selected from Mg, Ca, Sr, and Ba, and Al, Si, O, and N.

9. The luminescent material of claim 4, wherein an amount of the yellow phosphor is the largest, an amount of the red phosphor is the smallest, and an amount of the green phosphor is less than that of the yellow phosphor and greater than that of the red phosphor.

10. A light emitting device, comprising:

a substrate;

a light emitting diode having active layer provided between first and second semiconductor layer, the first semiconductor layer includes a first superlattice structure and the second semiconductor layer includes a layer having Al, Ga and N,

phosphor provided over the light emitting diode, the phosphor including a yellow phosphor, a green phosphor and red phosphor, wherein by weight, amount of yellow phosphor is greater than the red phosphor which is less than the green phosphor, and the amount of yellow phosphor and the green phosphor is different, wherein

at least one of a composition of Sr₃AlSi₂O_9/2N_8/3;

Eu, Sr₂AlSi₃O_7/2N₄;

Eu₂, Sr₂Al₃Si₂O_13/2N_8/3;

Eu₂, and the yellow phosphor comprises one of garnet-based phosphor, a silicate-based phosphor and nitride based phosphor,

the green phosphor emits light having a full width at half maximum (FWHM) of about 50 nm to about 100 nm, the yellow phosphor emits light having a FWHM of about 50 nm to about 100 nm or about 120 nm or more, and the red phosphor emits light having a FWHM of about 70 nm to about 120 nm, and

wherein the composition has a crystal structure in which a portion of a Si—

N bonding of a silicon nitride is substituted for an Al—

N bonding or an Al—

O bonding, and

further wherein said composition has peak wavelengths in different wavelength bands, and the crystal structure for the composition having one of the peak wavelengths in the different wavelength bands is different from the crystal structure of said composition having another one of the peak wavelengths in the different wavelength bands.

11. The light emitting device according to claim 10, wherein the light emitting diode emits one of UV light and blue light.

12. The light emitting device according to claim 10, wherein at least one peak intensity of light in a wavelength of about 350 to about 480 nm is included in the light emitted by the light emitting diode.

13. The light emitting device according to claim 10, further comprising an encapsulant surrounds the light emitting diode, and

wherein the yellow phosphor, the green phosphor and the red phosphor are dispersed and distributed in the encapsulant.

14. The light emitting device according to claim 10, wherein the first superlattice structure comprises a first conductive type InGaN/GaN superlattice structure or InGaN/InGaN superlattice structure disposed between the first conductive type semiconductor layer and the active layer.

15. The light emitting device according to claim 10, wherein the second semiconductor layer comprises a second conductive type AlGaN layer disposed between the second conductive type semiconductor layer and the active layer.

16. The light emitting device according to claim 10, wherein the green phosphor is an oxynitride (ON)-based phosphor or a silicate-based phosphor.

17. The light emitting device according to claim 10, wherein the yellow phosphor is a YAG phosphor, a TAG phosphor, or a silicate-based phosphor.

18. The light emitting device according to claim 10, wherein the red phosphor is a phosphor having at least one element selected from Mg, Ca, Sr, and Ba, and Al, Si, O, and N.