Sialon phosphor, process for producing the same, and illuminator and luminescent element employing the same

Abstract

Phosphor that can provide white LED that uses a blue LED or an ultraviolet LED as a light source and that has superior luminous efficiency. This phosphor includes, as a main component, α-type sialon represented by a general expression: (M1)x(M2)y(Si,Al) 12 (O,N) 16 (where M1 is one or more types of elements selected from a group consisting of Li, Mg, Ca, Y, and lanthanide element (except for La and Ce) and M2 is one or more types of elements selected from a group consisting of Ce, Pr, Eu, Tb, Yb, and Er, and 0.3≦X+Y≦1.5 and 0<Y≦0.7 are established and the sialon phosphor consists of a powder having a specific surface area of 0.2 to 0.5 m 2 /g.

1 - 18 . (canceled) 
     
     
         19 . A sialon phosphor,
 wherein the phosphor is composed of host material of β-type sialon represented by a general expression of Si 6-z Al z O z N 8-z  (wherein 0.01≦z≦4.2) and includes 0.01 to 10 atm % of a metal element M3, wherein M3 is one or more types of elements selected from among Mn, Ce, and Eu,   the constituent particles of said phosphor have an average circularity degree of 0.75 or more, a particle size distribution D 50  of 5 to 30 μm, and D 10  of 2.0 μm or more,   the particles of said phosphor includes light emission-related elements that have a low concentration in the interior of the particle and that have a high concentration at the outer periphery of the particle, and   the light emission-related element at the outer periphery of the phosphor particle has a concentration 1.2 times or more higher than that of the light emission-related element at the interior of the particle.   
     
     
         20 . The sialon phosphor according to  claim 19 ,
 wherein 0.1≦z≦0.5 is established in the general expression and M3 is Eu and has a content from 0.03 to 0.3 atm %.   
     
     
         21 - 25 . (canceled)