| abstract |
According to one embodiment, the luminescent material exhibits a luminescence peak in a wavelength ranging from 490 to 580 nm when excited with light having an emission peak in a wavelength ranging from 250 to 500 nm. The luminescent material has a diffraction peak intensity of the largest peak detected at 2θ = 30.1-31.1° that is higher than the diffraction peak intensity of the peak detected at 2θ = 25.0-26.0° in X-ray diffraction by the Bragg-Brendano method using Cu-Kα line and its composition is represented by (Sr 1-x Eu x )3- y Al 3 + z Si 13-z O 2+u N 21-w (a part of the Sr may be substituted by at least one selected from Ba, Ca, Mg and Na, 0<x≤1, -0.1≤y≤0.3, -3≤z≤-0.52, and -1.5≤u≤-0.3, -3<u-w≤1). |