Phosphor and method of preparing same

Patent metadata

Field	Value
Publication number	US-2016017222-A1
Application number	US-201514803566-A
Country	US
Kind code	A1
Filing date	Jul 20, 2015
Priority date	Jul 18, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

Disclosed is a phosphor including at least one of a nitride and an oxynitride, wherein the nitride and the oxynitride contain an alkaline-earth metal element, silicon, and an activator element. wherein the phosphor has a volume average particle diameter of greater than or equal to about 50 nm and less than or equal to about 400 nm and an inner quantum efficiency of greater than or equal to about 60% at an excitation wavelength of about 450 nm. The method of preparing a phosphor includes a precursor preparation process of preparing a phosphor precursor particles including a silicon nitride particles, a compound containing an alkaline-earth metal element, and a compound containing an activator element, wherein the compound containing an alkaline-earth metal element and the compound containing an activator element are deposited on the surface of the silicon nitride particles; and a firing process of firing the phosphor precursor particles.

First claim

What is claimed is:

1 . A phosphor comprising at least one of a nitride and an oxynitride, wherein the nitride and the oxynitride comprise an alkaline-earth metal element, silicon, and an activator element, and further wherein the phosphor has
a volume average particle diameter of greater than or equal to about 50 nm and less than or equal to about 400 nm, and an inner quantum efficiency of greater than or equal to about 60% at an excitation wavelength of about 450 nm.

2 . The phosphor of claim 1 , wherein the phosphor is represented by a formula of MSi 2 O 2 N 2 , and
the oxynitride has a crystal structure of SrSi 2 O 2 N 2 , and further wherein the element M comprises at least one alkaline-earth metal element comprising at least Sr and an optional additional alkaline-earth metal selected from Ca, Sr, Ba, and Mg, and at least one activator element comprising at least Eu or a combination of Eu and Ce, and M comprises Sr at greater than or equal to about 15 mol % and less than or equal to about 99 mol % and the activator element at greater than or equal to about 1 mol % and less than or equal to about 20 mol % based on the total amount of the M element.

3 . The phosphor of claim 1 , having a volume average particle-size distribution index of greater than or equal to about 1.20 and less than or equal to about 1.35.

4 . The phosphor of claim 2 , comprising a silicon-comprising compound having a different crystal structure from the oxynitride,
wherein the oxynitride is included at greater than or equal to about 50 mass % based on the total amount of the oxynitride and the silicon-comprising compound.

5 . A method of preparing a phosphor, comprising at least one of a nitride and an oxynitride wherein the nitride and the oxynitride comprise an alkaline-earth metal element, silicon, and an activator element, the method comprising:
a precursor preparation process comprising preparing phosphor precursor particles comprising silicon nitride particles, a compound comprising an alkaline-earth metal element, and a compound comprising an activator element, wherein the compound comprising the alkaline-earth metal element and the compound comprising the activator element are deposited on the surface of the silicon nitride particles, and further wherein the phosphor precursor particles have a volume average particle diameter of less than or equal to about 250 nm; and a firing process comprising firing the phosphor precursor particles.

6 . The method of claim 5 , wherein the precursor preparation process comprises applying a wet chemical method to a suspension comprising silicon nitride particles, a material comprising the alkaline-earth metal element, and a material comprising the activator element, to provide phosphor precursor particles in which the compound comprising the alkaline-earth metal element, and the compound comprising the activator element, are mixed with each other and deposited on the surface of the silicon nitride particles.

7 . The method of claim 5 , wherein the phosphor precursor particles comprise silicon nitride particles, a compound comprising at least one alkaline-earth metal element comprising at least Sr and optionally an alkaline-earth metal element selected from Ca, Sr, Ba, and Mg, and a compound comprising at least one activator element comprising Eu or a combination of Eu and Ce, wherein the compound comprising at least one alkaline-earth metal element and the compound comprising at least one activator element are deposited on the surface of the silicon nitride particles in a mole ratio of the total amount of the alkaline-earth metal element and the activator element to the silicon of about 1:1.4 to about 1:2.86, and
the phosphor precursor particles comprise Sr at greater than or equal to about 15 mol % and less than or equal to about 99 mol % and the activator element at greater than or equal to about 1 mol % and less than or equal to about 20 mol % based on the total amount of the alkaline-earth metal element and the activator element.

8 . The method of claim 7 , wherein the precursor preparation process comprises:
a suspension forming process comprising providing a suspension comprising silicon nitride particles, a material comprising at least one alkaline-earth metal element comprising at least Sr and optionally an additional alkaline-earth metal element selected from Ca, Sr, Ba, and Mg, and a material comprising at least one activator element comprising Eu or a combination of Eu and Ce to provide a mole ratio of the total amount of the alkaline-earth metal element and the activator element to the silicon in a range of 1:1.14 to 1:2.86; and a precursor forming process comprising applying a wet chemical method to the suspension to precipitate the compound comprising the alkaline-earth metal element and the compound comprising the activator element and to provide a phosphor precursor particles in which the compound comprising the alkaline-earth metal element and the compound comprising the activator element are mixed with each other and deposited on the surface of the silicon nitride particles, wherein the suspension comprises Sr at greater than or equal to about 15 mol % and less than or equal to about 99 mol % and the activator element at greater than or equal to about 1 mol % and less than or equal to about 20 mol % based on the total amount of the alkaline-earth metal element and the activator element.

9 . The method of claim 6 , wherein the wet chemical method is at least one of a co-precipitation method and a citrate process.

10 . The method of claim 9 , wherein the wet chemical method is a co-precipitation method.

11 . The method of claim 5 , wherein each of the compound comprising the alkaline-earth metal element and the compound comprising the activator element comprises at least one selected from a carbonate, a hydrogen carbonate, a phosphate, a carboxylate, an oxalate, a sulfate, an organometallic compound, and a hydroxide.

12 . The method of claim 11 , wherein each of the compound comprising the alkaline-earth metal element and the compound comprising the activator element comprises at least one compound selected from a carbonate and a hydroxide.

13 . The method of claim 5 , wherein the silicon nitride particles have a volume average particle diameter of less than or equal to about 150 nm.

14 . The method of claim 5 , wherein the silicon nitride particles are amorphous.

15 . The method of claim 5 , wherein the firing process is performed under a mixed gas atmosphere of hydrogen and nitrogen or a mixed gas atmosphere of ammonia and nitrogen at a temperature of greater than or equal to about 1150° C. and less than or equal to about 1650° C.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kitabatake Takuya
• Fujibayashi Fusaki
• Endo Hiroko
• Yamada Masahide
• Seto Takatoshi

Classifications

• C09K11/77347 Primary

  Silicon Nitrides or Silicon Oxynitrides · CPC title

• C09K11/7734 Primary

  Aluminates · CPC title