| abstract |
According to one embodiment, the luminescent material shows a luminescence peak in a wavelength range of 570 to 670 nm when excited with light having an emission peak in a wavelength range of 250 to 520 nm. The luminescent material includes a host material having a crystal structure substantially same as the crystal structure of Sr 2 Si 7 Al 3 ON 13 . The host material is activated by Eu, and includes Sr and Ca to satisfy a relationship of 0.008≦M Ca /(M Sr +M Ca )≦0.114, where M Ca is a number of moles of Ca and M Sr is a number of moles of Sr. |