| abstract |
Provided is an oxynitride phosphor powder which has a fluorescence peak wavelength of 610 to 625 nm and also has higher external quantum efficiency than the conventional one. The oxynitride phosphor powder according to the present invention is characterized by comprising an α-type SiAlON represented by the compositional formula: Ca x1 Eu x2 Si 12-(y+z) Al (y+z) O z N 16-z (wherein x1, x2, y, z fulfil the following formulae: 1.60 ≤ x1+x2 ≤ 2.90, 0.18 ≤ x2/x1 ≤ 0.70, 4.0 ≤ y ≤ 6.5, 0.0 ≤ z ≤ 1.0) and aluminum nitride. It is preferred that the powder additionally contains Li in an amount of 50 to 10000 ppm. It is also preferred that the content of aluminum nitride in the powder is 0 to 33 mass% exclusive. |