abstract |
An oxynitride phosphor powder includes an α-sialon fluorescent body having a fluorescent peak wavelength of 605-615 nm, and the external quantum efficiency of the oxynitride phosphor powder is greater than the conventional art. The oxynitride phosphor powder includes an α-sialon represented by the formula Ca x1 Eu x2 Si 12-(y+z) Al (y+z) O z N 16-z (where x1, x2, y, and z satisfy the expressions 1.10≦x1+x2≦1.70, 0.18≦x2/x1≦0.47, and 2.6≦y≦3.6, 0.0≦z≦1.0). |