EUROPIUM-ACTIVATED, BETA-SiAlON BASED GREEN PHOSPHORS

Abstract

Embodiments of the present invention are directed a β-SiAlON:Eu 2+ based green emitting phosphor having the formula Eu x (A1) 6−z (A2) z O y N 8−z (A3) 2(x+z−y) , where 0<z≦4.2; 0≦y≦z; 0<x≦0.1; A1 is Si, C, Ge, and/or Sn; A2 is Al, B, Ga, and/or In; A3 is F, Cl, Br, and/or I. The new set of compounds described by Eu x (A1) 6−z (A2) z O y N 8−z (A3) 2(x+z−y) have the same structure as β-Si 3 N 4 . Both elements A1 and A2 reside on Si sites, and both O and N occupy the nitrogen sites of the β-Si 3 N 4 crystal structure. A molar quantity (z−y) of the A3 − anion (defined as a halogen) reside on nitrogen sites.

1 . A β-SiAlON:Eu 2+  based green emitting phosphor having the formula 
       Eu x (A1) 6−z (A2) z O y N 8−z (A3) 2(x+z−y) , where the parameters x, y, and z have the values:
 0<z≦0.5; 
 y=z; and 
 0<x≦0.1; 
 
        and where
 A1 is Si; 
 A2 is Al; and 
 A3 is F 
 
        and wherein said β-SiAlON:Eu 2+  based green emitting phosphor is a crystalline material characterized by 2 l x-ray diffraction peaks at about 23.1, 26.8, 33.3, 35.8, 41.0 and 51.8 degrees and the absence of peaks at about 33.7 and 37.6 degrees. 
     
     
         2 . The β-SiAlON:Eu 2+  based green emitting phosphor of  claim 1 , wherein the A1 and A2 elements reside substantially on silicon (Si) sites. 
     
     
         3 . The β-SiAlON:Eu 2+  based green emitting phosphor of  claim 1 , wherein a quantity (z−y) of the A3 −  anion resides on nitrogen (N) sites. 
     
     
         4 . The β-SiAlON:Eu 2+  based green emitting phosphor of  claim 1 , wherein the phosphor has the formula Eu 0.02 Si 5.5 Al 0.5 O 0.5 N 7.5 F 0.04 . 
     
     
         5 . The β-SiAlON:Eu 2+  based green emitting phosphor of  claim 1 , wherein the phosphor has the formula Eu 0.02 Si 5.77 Al 0.23 O 0.23 N 7.77 F 0.04 . 
     
     
         6 . The β-SiAlON:Eu 2+  based green emitting phosphor of  claim 1 , wherein the phosphor has the formula Eu 0.02 Si 5.85 Al 0.15 O 0.15 N 7.85 F 0.04 .