Phosphor and production method of the same and light source and LED using the phosphor

• US 7,291,289 B2
• Filed: 08/20/2004
• Issued: 11/06/2007
• Est. Priority Date: 05/14/2004
• Status: Expired due to Fees

• Current Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Original Assignee: Dowa Electronics Materials Co. Ltd. (DOWA Holdings Company Limited)
• Inventors: Gotoh, Masahiro, Nagatomi, Akira, Yamashita, Shuji, Sakane, Kenji
• Primary Examiner(s): KOSLOW, CAROL M
• Application Number:
  US10/922,086
• Publication Number:
  US 20050253500A1
• Time in Patent Office: 1,173 Days
• Field of Search: 252/301.4 F, 252/301.6 F, 257/98, 313/503
• US Class Current: 252/301.40F
• CPC Class Codes: C09K 11/0838 Aluminates; Silicates
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A phosphor with high efficiency having an excitation band corresponding to light of the ultraviolet-visible (300 to 550 nm) wavelength region emitted from a light emitting element which emits blue or ultraviolet light is provided. Commercially available CaO [3N], Si₃N₄ [3N], and Eu₂O₃ [3N] are prepared, respective materials are weighed and mixed to have a mol ratio of CaO:Si₃N₄:Eu₂O₃=1.4775:1:0.01125, and then the mixture is heated to 1600° C. by a heating rate of 15° C./min under a nitrogen atmosphere and retained and fired at 1600° C. for three hours. Thereafter, the raw materials are cooled down from 1600° C. to 200° C. for an hour to thereby produce a phosphor having a composition formula Ca_1.58Si₃O_1.63N_4.35:Eu_0.024.

Claims

1. A phosphor represented by a general formula M_a+pSi₃O_a+qN_4+r:

Z, wherein M is a divalent element, Z is an element to be an activator, “

a”

is in a range of 0<

a≦

10, “

p”

is in a range of −

a/2<

p<

a/2, “

q”

is in a range of −

a/2<

q<

2a, and “

r”

is in a range of −

2<

r<

2.

2. The phosphor according to claim 1, wherein M is at least one or more elements selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, and mercury, and Z is at least one or more elements selected from rare-earth elements or transition metal elements.

3. The phosphor according to claim 1, wherein “

a”

is in a range of 0<

a≦

6.

4. The phosphor according to claim 1, wherein M is at least one or more elements selected from the group consisting of magnesium, calcium, strontium, barium, and zinc.

5. The phosphor according to claim 1, wherein Z is at least one or more elements selected from the group consisting of europium, manganese, and cerium.

6. The phosphor according to claim 1, wherein Z is europium.

7. The phosphor according to claim 1, wherein M is calcium.

8. The phosphor according to claim 1, wherein M is strontium.

9. The phosphor according to claim 1, wherein Z content is 0.0001 mol or more and 0.5 mol or less when the corresponding M is one mol.

10. The phosphor according to claim 1, wherein said phosphor is in a powder form.

11. The phosphor according to claim 10, wherein an average particle size of said phosphor is 20 μ

m or less and 0.1 μ

m or more.

13. A light source, comprising:

a phosphor according to claim 1; and

a light emitting portion.

14. The light source according to claim 13, wherein a wavelength of light emitted by said light emitting portion is from 300 nanometers to 550 nanometers.

15. A light emitting diode, comprising:

a phosphor according to claim 1; and

a light emitting portion.

16. The light emitting diode according to claim 15, wherein a wavelength of light emitted by said light emitting portion is from 300 nanometers to 550 nanometers.

12. A production method of a phosphor which is represented by a general formula M_a+pSi₃O_a+qN_4+r:

Z, in which M is a divalent element, Z is an element to be an activator, “

a”

is in a range of 0<

a≦

10, “

p”

is in a range of −

a/2<

p<

a/2, “

q”

is in a range of −

a/2<

q<

2a, and “

r”

is a −

2<

r<

2,

wherein one or more kind selected from an oxide, a carbonate, a nitride, a hydroxide, and a basic carbonate of M is used as a raw material of M, a silicon dioxide and/or a silicon nitride are/is used as a raw material of the silicon, and a silicon nitride and/or a nitride of M are/is used as a raw material of N, comprising the steps of;

mixing these raw materials to manufacture a mixture; and

firing the mixture thus obtained.