Patent ID: 8450923

Claim:
A light-emitting device comprising: a light-emitting element which exhibits light having a wavelength ranging from 250 to 500 nm; and a luminescent material layer disposed on the light-emitting element; wherein the luminescent material layer comprises a luminescent material which exhibits a light emission peak in a wavelength ranging from 490 to 580 nm when excited with light having a wavelength ranging from 250 to 500 nm and it has a composition represented by the following general formula (2): (M 1-x R x ) a2 AlSi b2 O c2 N d2 (2) wherein in the general formula (2), M comprises at least Sr; R comprises at least Eu; and x, a2, b2, c2 and d2 satisfy following relationships: 0≦x≦1, 0.93<a2<1.3, 4.0<b2<5.8, 0.6<c2<1, 6<d2<11, wherein the luminescent material contains one component concurrently indicating diffraction peaks at diffraction angles (2θ) of 11.81-11.85°, 15.34-15.38°, 20.4-20.47°, and 23.74-23.86°, in the X-ray diffraction where CuKα characteristic X-rays having wavelength of 1.54056 Å.