WHITE LIGHT-EMITTING DEVICE AND ILLUMINATION DEVICE

• US 20130264937A1
• Filed: 03/15/2013
• Published: 10/10/2013
• Est. Priority Date: 10/15/2010
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Mitsubishi Chemical Corporation (Mitsubishi Chemical Group Corp.)
• Inventors: SAKUTA, Hiroaki, KIJIMA, Naoto, HONG, Byungchul, SATOU, Yoshihito
• Granted Patent: US 8,890,403 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/57 containing manganese or rhenium
• CPC Class Codes: C09K 11/617 Silicates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

The present invention provides a technology that allows reducing the used amount of a Mn⁴⁺-activated fluoride complex phosphor without loss of luminous efficiency, in a white light-emitting device that is provided with the Mn⁴⁺-activated fluoride complex phosphor and an LED element that is an excitation source of the phosphor.

The present invention provides a white light-emitting device comprises a blue LED element, as well as a yellow phosphor and/or a green phosphor and a red phosphor as phosphors that are excited by the blue LED element. The red phosphor contains a Mn⁴⁺-activated fluoride complex phosphor and a Eu²⁺-activated alkaline earth silicon nitride phosphor.

Claims

1. A white light-emitting device comprising:

an LED element that emits blue light; and

a resin composition that contains a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element that emits blue light, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element that emits blue light,

wherein the phosphor that emits red light contains at least a Mn⁴⁺-activated fluoride complex phosphor and an Eu²⁺-activated alkaline earth silicon nitride phosphor, and

a content ratio of the Eu²⁺-activated alkaline earth silicon nitride phosphor with respect to the total of the Mn⁴⁺-activated fluoride complex phosphor and Eu²⁺-activated alkaline earth silicon nitride phosphor contained in the resin composition ranges from 0.5 wt % to 14.0 wt %.

3. The white light-emitting device according to claim 1 or 2, wherein λ

_R1−

20≦

λ

_R2≦

λ

_R1+30 is satisfied where λ

_R1 nm is an emission peak wavelength of the Mn⁴⁺-activated fluoride complex phosphor and λ

_R2 nm is an emission peak wavelength of the Eu²⁺-activated alkaline earth silicon nitride phosphor.

4. The white light-emitting device according to claim 1 or 2, wherein a maximum peak wavelength in an emission spectrum of the Eu²⁺-activated alkaline earth silicon nitride phosphor ranges from 600 to 630 nm.

5. The white light-emitting device according to claim 3, wherein the Mn⁴⁺-activated fluoride complex phosphor is KSF or KSNAF.

6. The white light-emitting device according to claim 3, wherein the Eu²⁺-activated alkaline earth silicon nitride phosphor is Sr_yCa_1-yAlSiN₃:

Eu.

7. The white light-emitting device according to claim 1 or 2, wherein the phosphor that emits yellow light is a (Y_1-u,Gd_u)₃(Al_1-vGa_v)₅O₁₂:

Ce,Eu phosphor (where u and v are 0≦

u≦

0.3 and 0≦

v≦

0.5, respectively) or Ca_1.5xLa_3-xSi₆N₁₁;

Ce (where x is 0≦

x≦

1).

8. The white light-emitting device according to claim 1 or 2, wherein the Mn⁴⁺-activated fluoride complex phosphor is dispersed in a cured product of a resin paste.

9. The white light-emitting device according to claim 8, wherein a base resin of the resin paste is a silicone resin.

10. The white light-emitting device according to claim 1 or 2, wherein a correlated color temperature of emitted white light ranges from 1600 to 4000K.

11. The white light-emitting device according to claim 1 or 2, wherein a correlated color temperature of emitted white light ranges from 2500 to 3500K.

12. The white light-emitting device according to claim 1 or 2, wherein a blending proportion of the Mn⁴⁺-activated fluoride complex phosphor contained in the resin composition ranges from 10 wt % to 50 wt %, and

a blending proportion of the Eu²⁺-activated alkaline earth silicon nitride phosphor contained in the resin composition ranges from 0.1 wt % to 5.0 wt %.

26. The white light-emitting device according to any one of claim 1, 2, 22, or 23, wherein the LED element and the resin composition are placed to make a interspace between the LED element and the resin composition.

28. An illumination device, comprising the white light-emitting device according to any one of claims 1, 2, 22, 23 or 27.

2. A white light-emitting device comprising:

an LED element; and

a resin composition that contains a phosphor that emits blue light through wavelength conversion of light emitted by the LED element, a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element,

wherein the phosphor that emits red light contains at least a Mn⁴⁺-activated fluoride complex phosphor and an Eu²⁺-activated alkaline earth silicon nitride phosphor, and

a content ratio of the Eu²⁺-activated alkaline earth silicon nitride phosphor with respect to the total of the Mn⁴⁺-activated fluoride complex phosphor and Eu²⁺-activated alkaline earth silicon nitride phosphor contained in the resin composition ranges from 0.5 wt % to 14.0 wt %.

13. A white light-emitting device, comprising:

an LED element that emits blue light;

a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element that emits blue light; and

a phosphor that emits red light through wavelength conversion of light emitted by the LED element that emits blue light;

or comprising;

an LED element;

a phosphor that emits blue light through wavelength conversion of light emitted by the LED element;

a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element; and

a phosphor that emits red light through wavelength conversion of light emitted by the LED element,

wherein the phosphor that emits red light contains a Mn⁴⁺-activated fluoride complex phosphor dispersed in a first translucent matrix and an Eu²⁺-activated alkaline earth silicon nitride phosphor dispersed in a second translucent matrix, and

a content ratio of the Eu²⁺-activated alkaline earth silicon nitride phosphor with respect to the total of the Mn⁴⁺-activated fluoride complex phosphor and Eu²⁺-activated alkaline earth silicon nitride phosphor ranges from 0.5 wt % to 14.0 wt %.

14. The white light-emitting device according to claim 13, wherein a refractive index of the first translucent matrix is lower than a refractive index of the second translucent matrix.

15. The white light-emitting device according to claim 14, wherein all the phosphors, except the Mn⁴⁺-activated fluoride complex phosphor, are dispersed in the second translucent matrix.

16. The white light-emitting device according to claim 13, wherein the first translucent matrix is a cured product of a resin paste.

17. The white light-emitting device according to claim 16, wherein a base resin of the resin paste is a silicone resin.

18. The white light-emitting device according to claim 17, wherein a refractive index of the silicone resin is smaller than 1.45.

19. The white light-emitting device according to claim 13, wherein a correlated color temperature of emitted white light ranges from 1600 to 4000K.

20. The white light-emitting device according to claim 13, wherein a correlated color temperature of emitted white light ranges from 2500 to 3500K.

21. The white light-emitting device according to claim 13, wherein the LED element, the first translucent matrix and the second translucent matrix are placed to make a interspace between the LED element, and the first translucent matrix and the second translucent matrix.

22. A white light-emitting device comprising:

an LED element that emits blue light; and

a resin composition that contains a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element that emits blue light, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element that emits blue light,

wherein the phosphor that emits red light contains at least a red phosphor having a narrow-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 20 nm or less, and a red phosphor having a broad-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 80 nm or more, and

a content ratio of the red phosphor having the broad-band emission spectrum with respect to the total of the red phosphor having the narrow-band emission spectrum and the red phosphor having the broad-band emission spectrum that are contained in the resin composition ranges from 0.5 wt % to 14.0 wt %.

24. The white light-emitting device according to claim 22 or 23, wherein a blending proportion of the red phosphor having the narrow-band emission spectrum and contained in the resin composition ranges from 10 wt % to 50 wt %.

25. The white light-emitting device according to claim 22 or 23, wherein a blending proportion of the red phosphor having the broad-band emission spectrum and contained in the resin composition ranges from 0.1 wt % to 5.0 wt %.

23. A white light-emitting device comprising:

an LED element; and

a resin composition that contains a phosphor that emits blue light through wavelength conversion of light emitted by the LED element, a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element,

wherein the phosphor that emits red light contains at least a red phosphor having a narrow-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 20 nm or less, and a red phosphor having a broad-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 80 nm or more, and

a content ratio of the red phosphor having the broad-band emission spectrum with respect to the total of the red phosphor having the narrow-band emission spectrum and the red phosphor having the broad-band emission spectrum that are contained in the resin composition ranges from 0.5 wt % to 14.0 wt %.

27. A white light-emitting device comprising:

an LED element that emits blue light; and

a translucent matrix that contains a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element that emits blue light, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element that emits blue light;

or comprising;

an LED element; and

a translucent matrix that contains a phosphor that emits blue light through wavelength conversion of light emitted by the LED element, a phosphor that emits yellow light and/or a phosphor that emits green light through wavelength conversion of light emitted by the LED element, and a phosphor that emits red light through wavelength conversion of light emitted by the LED element,

wherein the phosphor that emits red light contains at least a red phosphor having a narrow-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 20 nm or less, and a red phosphor having a broad-band emission spectrum such that a maximum emission peak thereof ranges from 600 nm to 660 nm and the full width at half maximum of a red emission peak is 80 nm or more, and

a content ratio of the red phosphor having the broad-band emission spectrum with respect to the total of the red phosphor having the narrow-band emission spectrum and the red phosphor having the broad-band emission spectrum that are contained in the translucent matrix ranges from 0.5 wt % to 14.0 wt %.