CHLOROSILICATE FLUORESCENT MATERIAL, METHOD FOR PRODUCING THE SAME, AND LIGHT EMITTING DEVICE

• US 20200131437A1
• Filed: 10/23/2019
• Published: 04/30/2020
• Est. Priority Date: 10/25/2018
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: MIYAI, Ryuta, NISHIMATA, Kazuya, HOSOKAWA, Shoji
• Granted Patent: US 11,732,187 B2
• Time in Patent Office: Days
• CPC Class Codes: C09K 11/617 Silicates
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: H01L 33/26 Materials of the light emitting region
• 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: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Provided are a chlorosilicate fluorescent material having high light emission efficiency, a method for producing the same, and a light emitting device. In certain embodiments, the chlorosilicate fluorescent material has a chemical composition comprising Ca, Eu, Mg, Si, O, and Cl, wherein when a molar ratio of Si in 1 mol of the chemical composition is set as 4, the chlorosilicate fluorescent material comprises Ca in a molar ratio range of 7.0 or more and 7.94 or less, Eu in a molar ratio range of 0.01 or more and 1.0 or less, Ca and Eu in a total molar ratio range of 7.70 or more and 7.95 or less, Mg in a molar ratio range of 0.9 or more and 1.1 or less, and Cl in a molar ratio range of more than 1.90 and 2.00 or less.

Claims

1. A chlorosilicate fluorescent material, having a chemical composition comprising Ca, Eu, Mg, Si, O, and Cl,

wherein when a molar ratio of Si in 1 mol of the chemical composition is set as 4, the chlorosilicate fluorescent material comprises Ca in a molar ratio range of 7.0 or more and 7.94 or less, Eu in a molar ratio range of 0.01 or more and 1.0 or less, Ca and Eu in a total molar ratio range of 7.70 or more and 7.95 or less, Mg in a molar ratio range of 0.9 or more and 1.1 or less, and Cl in a molar ratio range of more than 1.90 and 2.00 or less.

2. The chlorosilicate fluorescent material according to claim 1, having the chemical composition represented by the following formula (I):

Ca_xEu_yMg_zSi₄O_aCl_b  

 

(I)

wherein a, b, x, y, and z each satisfy 7.0≤

x≤

7.94, 0.01≤

y≤

1.0, 7.70≤

x+y≤

7.95, 0.9≤

z≤

1.1, 15.6≤

a≤

16.1, and 1.90<

b≤

2.00.

3. The chlorosilicate fluorescent material according to claim 2, wherein in the formula (I), x, y, a, and b each satisfy 7.80≤

x+y≤

7.95, 15.73≤

a≤

16.05, and 1.95≤

b<

2.00.

4. The chlorosilicate fluorescent material according to claim 1, comprising a fluorescent material core having the chemical composition and an oxide adhered on the surface of the fluorescent material core, wherein the oxide is at least one oxide selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, and TiO₂.

5. The chlorosilicate fluorescent material according to claim 2, comprising a fluorescent material core having the chemical composition and an oxide adhered on the surface of the fluorescent material core, wherein the oxide is at least one oxide selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, and TiO₂.

6. A light emitting device, comprising:

a light source having a light emission peak wavelength in a range of 250 nm or more and 485 nm or less; and

the chlorosilicate fluorescent material according to claim 1.

7. A light emitting device, comprising:

a light source having a light emission peak wavelength in a range of 250 nm or more and 485 nm or less; and

the chlorosilicate fluorescent material according to claim 2.

8. A method for producing a fluorescent material, comprising:

providing a compound containing Ca, a compound containing Eu, a compound containing Mg, a compound containing Si, and a compound containing Cl such thata molar ratio of Ca is in a range of 7 or more and 8.2 or less, a molar ratio of Eu is in a range of 0.01 or more and 1.1 or less, a molar ratio of Mg is in a range of 0.9 or more and 1.1 or less, a total molar ratio of Ca and Eu is in a range of 8.05 or more and 8.25 or less, and a molar ratio of Cl is in a range of 2.0 or more and 3.0 or less when a molar ratio of Si in the compound containing Si is set as 4;

mixing each of the compound containing Ca, the compound containing Eu, the compound containing Mg, the compound containing Si, and the compound containing Cl to obtain a raw material mixture; and

calcining the raw material mixture to obtain a chlorosilicate fluorescent material,

wherein at least one of the compound containing Eu, the compound containing Mg, and the compound containing Si is an oxide, and the compound containing Cl optionally contains Ca or Mg.

9. The method for producing a fluorescent material according to claim 8, wherein the chlorosilicate fluorescent material has a chemical composition represented by the following formula (I):

Ca_xEu_yMg_zSi₄O_aCl_b  

 

(I)

wherein a, b, x, y, and z each satisfy 7.0≤

x≤

7.94, 0.01≤

y≤

1.0, 7.70<

x+y≤

7.95, 0.9≤

z≤

1.1, 15.6≤

a≤

16.1, and 1.90<

b≤

2.00.

10. The method for producing a fluorescent material according to claim 8, whereina temperature for calcining the raw material mixture is in a range of 1,000°

C. or more and 1, 300°

C. or less.

11. The method for producing a fluorescent material according to claim 8, wherein an atmosphere for calcining the raw material mixture is a reducing atmosphere.

12. The method for producing a fluorescent material according to claim 8, further comprising adhering on the chlorosilicate fluorescent material as a fluorescent material core at least one oxide selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, and TiO₂.

13. The method for producing a fluorescent material according to claim 9, further comprising adhering on the chlorosilicate fluorescent material as a fluorescent material core at least one oxide selected from the group consisting of Al₂O₃, SiO₂, ZrO₂, and TiO₂.