Emission Band Change of (Sr[sub 1−x]M[sub x])[sub 3]SiO[sub 5]:Eu[sup 2+] (M=Ca, Ba) Phosphor for White Light Sources Using Blue/Near-Ultraviolet LEDs

The luminescence properties of orange-yellow-emitting -activated were optimized for application to blue/near ultraviolet (n-UV) light-emitting diodes (LEDs). showed strong orange-yellow emission peaking at under blue and n-UV light of 450 and , respectively, and the effects of Ca and Ba substitutions into sites on the emission band change were investigated. For the substitution of Ca, showed no orange-yellow emission under blue light due to the different crystal structures of (monoclinic) and (tetragonal). The redshift and blueshift of the emission band of were explained by the competition between crystal field effect and Nephelauxetic effect. The -emitting blue LED-pumped white LED with or a mixture of and green phosphor were fabricated and they showed color coordinates of (0.343, 0.281) and (0.349, 0.339), respectively.