Blue-light-emitting phosphor and light-emitting device equipped with the blue-light-emitting phosphor

摘要

A blue light-emitting phosphor having an elemental formula of Sr_3-xMgSi₂O₈:Eu_x (wherein x represents a value in the range of 0.008 to 0.110), a merwinite crystal structure and a crystal lattice strain of 0.080% or less as determined from an X-ray diffraction pattern at diffraction angle 2θ of 20-130° by the Le Bail method, wherein the X-ray diffraction pattern is determined using a CuKα ray having an incident angle of θ, is used advantageously as a blue light-emitting material for a light-emitting device which comprises a semiconductor light-emitting element capable of emitting a light having a wavelength of 350-430 nm upon application of an electrical current, such as a white light-emitting LED lamp, and a blue light-emitting material capable of emitting a blue light upon excitation with a light emitted by the semiconductor light-emitting element.