Fluorescent substance containing nitrogen, method for manufacturing the same, and light-emitting device

Abstract

Disclosed is a method for manufacturing a nitrogen-containing fluorescent substance comprising accommodating an oxide fluorescent substance containing two or more elements in a receptacle made of a material containing carbon, and sintering the oxide fluorescent substance in a mixed gas atmosphere containing nitrogen gas.

1 . A nitrogen-containing fluorescent substance manufactured by the method comprising:
 accommodating an oxide fluorescent substance comprising two or more metal elements in a receptacle made of a material comprising carbon; and   sintering the oxide fluorescent substance accommodated in the receptacle made of a material comprising carbon in a mixed gas atmosphere comprising nitrogen gas.   
     
     
         2 . A nitrogen-containing fluorescent substance manufactured by the method comprising:
 sintering an oxide fluorescent substance represented by the following general formula (1) in a mixed gas atmosphere containing nitrogen gas, thereby converting at least part of the oxide fluorescent substance into a nitrogen-containing fluorescent substance represented by the following general formula (2):
   M 2 SiO 4 :Z  (1) 
   M 2 Si 5 N 8 :Z  (2) 
   wherein M is at least one selected from the group consisting of Sr, Ba and Ca; and Z is at least one activator selected from the group consisting of Eu and Ce.   
     
     
         3 . A light-emitting device comprising:
 a light-emitting element having a first emission spectrum; and   a fluorescent layer comprising a nitrogen-containing fluorescent substance of  claim 1 , the nitrogen-containing fluorescent substance shifting the wavelength of at least part of the first emission spectrum, thereby exhibiting a second emission spectrum formed of at least one emission band and falling within a different wavelength region from that of the first emission spectrum.   
     
     
         4 . A light-emitting device comprising:
 a light-emitting element having a first emission spectrum; and   a fluorescent layer comprising a nitrogen-containing fluorescent substance of  claim 2 , the nitrogen-containing fluorescent substance shifting the wavelength of at least part of the first emission spectrum, thereby exhibiting a second emission spectrum formed of at least one emission band and falling within a different wavelength region from that of the first emission spectrum.   
     
     
         5 . The nitrogen-containing fluorescent substance of  claim 2 , wherein the oxide fluorescent substance of formula (1) has a particle size ranging from 5 to 20 μm. 
     
     
         6 . The nitrogen-containing fluorescent substance of  claim 2 , wherein component Z of formula (2) is present in a molar ratio that satisfies: Z/(M+Z)=0.03−0.13. 
     
     
         7 . The nitrogen-containing fluorescent substance of  claim 2 , wherein the sintering occurs at a temperature of at least 1,600° C. 
     
     
         8 . The nitrogen-containing fluorescent substance of  claim 7 , wherein the temperature is from 1,600 to 1,700° C. 
     
     
         9 . The nitrogen-containing fluorescent substance of  claim 2 , wherein the nitrogen containing gas further comprises hydrogen. 
     
     
         10 . The nitrogen-containing fluorescent substance of  claim 9 , wherein hydrogen and nitrogen are present in a ratio ranging from 10:90 to 70:30. 
     
     
         11 . The nitrogen-containing fluorescent substance of  claim 2 , wherein Z in formula (2) represents Eu. 
     
     
         12 . The nitrogen-containing fluorescent substance of  claim 11 , wherein the oxide fluorescent compound of formula (2) absorbs a first emission spectrum at a wavelength ranging from 370 to 410 nm. 
     
     
         13 . The nitrogen-containing fluorescent substance of  claim 2 , wherein Z in formula (2) represents Ce. 
     
     
         14 . The nitrogen-containing fluorescent substance of  claim 13 , wherein the oxide fluorescent compound of formula (2) absorbs a first emission spectrum at a wavelength ranging from 370 to 430 nm. 
     
     
         15 . The nitrogen-containing fluorescent substance of  claim 1 , wherein sintering occurs at a temperature ranging of at least 1,600° C. 
     
     
         16 . The nitrogen-containing fluorescent substance of  claim 1 , wherein the nitrogen containing gas further comprises hydrogen. 
     
     
         17 . The nitrogen-containing fluorescent substance of  claim 7 , wherein hydrogen and nitrogen are present in a ratio ranging from 10:90 to 70:30.