Fluorescent substance, method of manufacturing the fluorescent substance, and light emitting device using the fluorescent substance

• US 9,708,531 B2
• Filed: 02/26/2010
• Issued: 07/18/2017
• Est. Priority Date: 02/26/2009
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Shinohara, Takayuki, Hosokawa, Shoji
• Primary Examiner(s): Hoban, Matthew E
• Assistant Examiner(s): Edmondson, Lynne
• Application Number:
  US13/203,444
• Publication Number:
  US 20110309399A1
• Time in Patent Office: 2,699 Days
• Field of Search: 2523014 R, 2523014 F, 313503, 313504, 313467, 313468, 257 98
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/16245 the item being metallic
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A fluorescent substance is provided having excellent temperature properties and capable of being excited by light in the region from near ultraviolet to short-wavelength visible light to emit light of yellow to red color. A process for producing the fluorescent substance, and a light emitting device using the fluorescent substance is also provided. The fluorescent substance includes M which is at least one group II element selected from Ca, Sr, and Ba, and Al, Si, O, and N, and activated with Eu. The fluorescent substance has an X-ray diffraction pattern using CuKα radiation, in which the intensity of the diffraction peak in the Bragg angle range of 17.9° to 18.5° is taken as 100%, the relative intensity of the diffraction peak is 150% to 310% in a Bragg angle range of 24.5° to 25.1° , and is 320% to 550% in a Bragg angle range of 34.8° to 35.4°.

Claims

1. A fluorescent substance that has an emission peak wavelength at 584 nm to 630 nm upon being excited by a light source of 460 nm, wherein:

the fluorescent substance is Sr_1.78Eu_0.22Al_5.73Si_7.39O_1.35N_15.62, and

the fluorescent substance has a formation phase whose main phase shows, in an X-ray diffraction pattern using CuKα

radiation with an intensity of a diffraction peak in a Bragg angle range of 17.9°

to 18.5°

taken as 100%, a relative intensity of the diffraction peak in a range of 150% to 310% in a Bragg angle range of 24.5°

to 25.1° and

a relative intensity of the diffraction peak in a range of 320% to 550% in a Bragg angle range of 34.8°

to 35.4°

.

2. The fluorescent substance according to claim 1, wherein a relative intensity of the diffraction peak is in a range of 190% to 460% in a Bragg angle range of 30.6°

to 31.2°

.

3. The fluorescent substance according to claim 1, wherein a relative intensity of the diffraction peak is in a range of 270% to 570% in a Bragg angle range of 35.7°

to 36.3°

.

4. The fluorescent substance according to claim 1, wherein a relative intensity of the diffraction peak is in a range of 160% to 320% in a Bragg angle range of 68.7°

to 69.3°

.

5. The fluorescent substance according to claim 1, wherein the formation phase belongs to orthorhombic system with lattice constant in a range of 4.4 Å

≦

a ≦

5.4 Å

, 7.0 Å

≦

b≦

8.0 Å

, and 11.1 Å

≦

c≦

12.1 Å

.

6. The fluorescent substance according to claim 1, wherein half bandwidth of emission spectra of the fluorescent substance is in a range of 100 nm to 125 nm.

7. A light emitting device comprising:

an excitation light source configured to emit light having a peak wavelength in a range from near-ultraviolet to short wavelength range of visible light, and

a fluorescent substance capable of absorbing a part of light from the excitation light source and emitting fluorescent light;

wherein the fluorescent substance comprises the fluorescent substance according to claim 1.

8. A fluorescent substance that has an emission peak wavelength at 584 nm to 630 nm upon being excited by a light source of 460 nm, wherein :

the fluorescent substance is Sr_1.78Eu_0.22Al_4.09Si_7.76O_1.30N_14.23, and

the fluorescent substance has a formation phase whose main phase shows, in an X-ray diffraction pattern using CuKα

radiation with an intensity of a diffraction peak in a Bragg angle range of 17.9°

to 18.5°

taken as 100%, a relative intensity of the diffraction peak in a range of 150% to 310% in a Bragg angle range of 24.5°

to 25.1° and

a relative intensity of the diffraction peak in a range of 320% to 550% in a Bragg angle range of 34.8°

to 35.4°

.

9. The fluorescent substance according to claim 8, wherein a relative intensity of the diffraction peak is in a range of 190% to 460% in a Bragg angle range of 30.6°

to 31.2°

.

10. The fluorescent substance according to claim 8, wherein a relative intensity of the diffraction peak is in a range of 270% to 570% in a Bragg angle range of 35.7°

to 36.3°

.

11. The fluorescent substance according to claim 8, wherein a relative intensity of the diffraction peak is in a range of 160% to 320% in a Bragg angle range of 68.7°

to 69.3°

.

12. The fluorescent substance according to claim 8, wherein the formation phase belongs to orthorhombic system with lattice constant in a range of 4.4 Å

≦

a ≦

5.4 Å

, 7.0 Å

≦

b≦

8.0 Å

, and 11.1 Å

≦

c≦

12.1 Å

.

13. The fluorescent substance according to claim 8, wherein half bandwidth of emission spectra of the fluorescent substance is in a range of 100 nm to 125 nm.

14. A light emitting device comprising:

an excitation light source configured to emit light having a peak wavelength in a range from near-ultraviolet to short wavelength range of visible light, and

a fluorescent substance capable of absorbing a part of light from the excitation light source and emitting fluorescent light;

wherein the fluorescent substance comprises the fluorescent substance according to claim 8.

15. A fluorescent substance that has an emission peak wavelength at 584 nm to 630 nm upon being excited by a light source of 460 nm, wherein :

the fluorescent substance is Sr_1.80Eu_0.209Al_4.19Si_7.71O_1.51N_14.79, and

the fluorescent substance has a formation phase whose main phase shows, in an X-ray diffraction pattern using CuKα

radiation with an intensity of a diffraction peak in a Bragg angle range of 17.9°

to 18.5°

taken as 100%, a relative intensity of the diffraction peak in a range of 150% to 310% in a Bragg angle range of 24.5°

to 25.1° and

a relative intensity of the diffraction peak in a range of 320% to 550% in a Bragg angle range of 34.8°

to 35.4°

.

16. The fluorescent substance according to claim 15, wherein a relative intensity of the diffraction peak is in a range of 190% to 460% in a Bragg angle range of 30.6°

to 31.2°

.

17. The fluorescent substance according to claim 15, wherein a relative intensity of the diffraction peak is in a range of 270% to 570% in a Bragg angle range of 35.7°

to 36.3°

.

18. The fluorescent substance according to claim 15, wherein a relative intensity of the diffraction peak is in a range of 160% to 320% in a Bragg angle range of 68.7°

to 69.3°

.

19. The fluorescent substance according to claim 15, wherein the formation phase belongs to orthorhombic system with lattice constant in a range of 4.4 Å

≦

a≦

5.4 Å

, 7.0 Å

≦

b≦

8.0 Å

, and 11.1 Å

≦

c≦

12.1 Å

.

20. The fluorescent substance according to claim 15, wherein half bandwidth of emission spectra of the fluorescent substance is in a range of 100 nm to 125 nm.

21. A light emitting device comprising:

an excitation light source configured to emit light having a peak wavelength in a range from near-ultraviolet to short wavelength range of visible light, and

a fluorescent substance capable of absorbing a part of light from the excitation light source and emitting fluorescent light;

wherein the fluorescent substance comprises the fluorescent substance according to claim 15.