Fluorescent substance and a production method therefor

• US 9,120,973 B2
• Filed: 02/06/2012
• Issued: 09/01/2015
• Est. Priority Date: 02/14/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Won, Hyong Sik, Kim, Seong Min, Min, Chan Suk, Yoon, Chul Soo
• Primary Examiner(s): Hoban, Matthew E
• Application Number:
  US13/985,398
• Publication Number:
  US 20140048742A1
• Time in Patent Office: 1,303 Days
• Field of Search: 252/301.4 F
• US Class Current: 1/1
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7728 containing europium
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides

Abstract

The fluorescent substance according to one embodiment of the present invention has the following compositional formula (1): [Compositional formula 1] Sr_ySi_(6−z)Al_zO_zN_(8−z):Re_x. Here, x, y and z are respectively 0.005≦x≦0.05, 0.05≦y≦0.5, 0.001≦z≦0.50, and Re is a rare earth element. As a result, the fluorescent substance according to one embodiment of the present invention can exhibit a short wavelength of between 525 nm and 537 nm when the concentration of strontium is between 0.05 moles and 0.5 moles. Also, the fluorescent substance can exhibit a short wavelength of between 525 nm and 537 nm by the addition of barium in a range of between 0.003 moles and 0.125 moles when the concentration of aluminium is high. Also, the fluorescent substance can exhibit a short wavelength of between 525 nm and 537 nm by adjusting the oxygen concentration by the addition not only of AlN but also of Al₂O₃ as an aluminium precursor when the concentration of aluminium is high. Ultimately, since the fluorescent substance according to one embodiment of the present invention can exhibit a short wavelength of between 525 nm and 537 nm, it is possible to prevent dropoff in colour reproduction and the colour rendering index.

Claims

1. A phosphor being represented by Formula 1:

Sr_ySi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 1]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.001≦

z≦

0.50, and Re is a rare-earth element.

2. The phosphor of claim 1, wherein z is 0.10 to 0.35.

3. The phosphor of claim 1, wherein the phosphor has a peak emission wavelength ranging from 525 nm to 537 nm when irradiated by an excitation source.

4. The phosphor of claim 1, wherein the rare-earth element is selected from the group consisting of Eu and Ce.

5. A phosphor being represented by Formula 2:

Sr_yBa_mSi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 2]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.50≦

z≦

1.0, 0.003≦

m≦

0.125, and Re is a rare-earth element.

6. The phosphor of claim 5, wherein m satisfies 0.01≦

m≦

0.125.

7. The phosphor of claim 5, wherein the phosphor has a peak emission wavelength ranging from 525 nm to 537 nm when irradiated by an excitation source.

8. A phosphor being represented by Formula 3:

Sr_ySi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 3]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.50≦

z≦

1.0, and Re is a rare-earth element.

9. The phosphor of claim 8, wherein z satisfies 0.58≦

z≦

0.75.

10. The phosphor of claim 8, wherein the phosphor has a peak emission wavelength ranging from 525 nm to 537 nm when irradiated by an excitation source.

11. A method of preparing a phosphor, the method comprising:

generating a mixture by mixing a strontium precursor, a silicon precursor, an aluminum precursor, and an activator precursor; and

sintering the mixture under a nitrogen atmosphere,

the phosphor being represented by Formula 1;

Sr_ySi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 1]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.001≦

z≦

0.50, and Re is a rare-earth element.

12. The method of claim 11, wherein the strontium precursor is SrCO₃.

13. The method of claim 11, wherein the aluminum precursor is selected from the group consisting of metallic aluminum and aluminum nitride.

14. The method of claim 11, wherein the activator precursor is a compound comprising a rare-earth element.

15. The method of claim 14, wherein the rare-earth element is selected from the group consisting of Eu and Ce.

16. The method of claim 11, wherein the sintering is carried out at 1,800°

C. to 2,200°

C.

17. The method of claim 11, wherein the sintering is carried out at a pressure of nitrogen gas of 0.1 MPa to 10 MPa.

18. A method of preparing a phosphor, the method comprising:

generating a mixture by mixing a strontium precursor, a barium precursor, a silicon precursor, an aluminum precursor, and an activator precursor; and

sintering the mixture under a nitrogen atmosphere,

the phosphor being represented by Formula 2;

Sr_yBa_mSi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 2]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.50≦

z≦

1.0, 0.003≦

m≦

0.125, and Re is a rare-earth element.

19. The method of claim 18, wherein the barium precursor is BaCO₃.

20. A method of preparing a phosphor, the method comprising:

generating a mixture by mixing a strontium precursor, a silicon precursor, an aluminum precursor, and an activator precursor; and

sintering the mixture under a nitrogen atmosphere,

the phosphor being represented by Formula 3;

Sr_ySi<sub>(6−

z)</sub>Al_zO_zN<sub>(8−

z)</sub>;

Re_x, 

 

[Formula 3]

where 0.005≦

x≦

0.05, 0.05≦

y≦

0.5, 0.50≦

z≦

1.0, and Re is a rare-earth element.

21. The method of claim 20, wherein the aluminum precursor is aluminum nitride and aluminum oxide.