| abstract |
A highly dispersible, monodisperse sialon-based oxynitride phosphor having a small difference in size between secondary particles and primary particles and less fusing and aggregation is obtained. Provided is a phosphor having uniform fluorescence and high emission intensity. An M x Si 12- (m + n ) Al (m + n) O n N 16-n: Ln y ( wherein, 0.3 ≦ x + y <1.5,0 <y <0.7,0.3 ≦ m <4.5 , 0 <n <2.25, m = ax + by), and α-sialon in which part or all of the metal M solid-solved in α-sialon is substituted with the lanthanide metal Ln serving as the center of light emission. The ratio A 1 = D 50 / D BET of 3.0 or less, or (B) the median diameter in the particle size distribution curve, with the main component being (A) the median diameter in the particle size distribution curve and the sphere equivalent diameter converted from the BET specific surface area Ratio with respect to primary particle diameter by scanning electron micrograph A 2 = D 50 / D particle An oxynitride phosphor having a particle size of 3.0 or less. [Selection figure] None |