Fluorescent material and light-emitting device employing the same

Abstract

The embodiment provides a process for production of a green light-emitting oxynitride fluorescent material having Sr 3 Al 3 Si 13 O 2 N 21 crystal structure, and also provides the fluorescent material produced by that process. An metal halide is adopted in the process as one of the starting material metal compounds. As the metal halide, a Ca or Na compound as well as a Sr compound can be preferably employed.

1 - 10 . (canceled) 
     
     
         11 . An oxynitride fluorescent material represented by the following formula (2):
   (M′ 1−x−x0 M 0   x0 R x ) 3−y Si 13−z Al 3+z O 2+u N 21−w    (2)
   
       in which M′ is an element selected from the IA group elements other than Na, the IIA group elements other than Ca, the IIIA group elements other than Al, the IIIB group elements, the rare earth elements, and the IVA group elements other than Si; M 0  is an element selected from the group consisting of Ca and Na; R is an element selected from the group consisting of Eu, Ce, Mn, Tb, Yb, Dy, Sm, Tm, Pr, Nd, Pm, Ho, Er, Cr, Sn, Cu, Zn, As, Ag, Cd, Sb, Au, Hg, Tl, Pb, Bi and Fe; and x, x0, y, z, u and w are numbers satisfying the conditions of 0<x≦1, 0<x0≦0.08, −0.1≦y≦0.15, −1≦z≦1, and −1<u−w≦1.5, respectively; and
 emitting luminescence having a peak in the wavelength range of 490 to 580 nm when excited with light in the wavelength range of 250 to 500 nm. 
 
     
     
         12 . The oxynitride fluorescent material according to  claim 11 , wherein M is selected from the group consisting of Li, K, Mg, Sr, B, Ga, In, Y, Sc, Gd, La, Lu and Ge. 
     
     
         13 - 15 . (canceled) 
     
     
         16 . A light-emitting device comprising
 a light-emitting element giving off light in the wavelength range of 250 to 500 nm, and   a phosphor layer which is provided on said light-emitting element and which contains the oxynitride fluorescent material according to  claim 11 .   
     
     
         17 . The oxynitride fluorescent material according to  claim 11 , wherein the chemical bond lengths of M′-N and M′-O calculated from the lattice constants and atomic coordinates determined by X-ray diffraction or neutron diffraction are within the range of ±15% based on those of Sr—N and Sr—O of Sr 3 Si 13 Al 3 O 2 N 21 , respectively. 
     
     
         18 . The oxynitride fluorescent material according to  claim 11 , wherein the material includes a compound having the Sr 3 Al 3 Si 13 O 2 N 21  crystal structure. 
     
     
         19 . The oxynitride fluorescent material according to  claim 11 , wherein positions of 10 peaks having strong diffraction in XRD profile of said material are identical with those in the XRD profile of Sr 3 Al 3 Si 13 O 2 N 21 . 
     
     
         20 . The device according to  claim 16 , which emits white emission. 
     
     
         21 . The device according to  claim 20 , wherein said material is used in combination with plural fluorescent materials emitting luminescence in other wavelength ranges. 
     
     
         22 . The device according to  claim 16 , wherein said device is a package cup-type light-emitting device or a shell-type light-emitting device.