| abstract |
The present invention relates to a red-emitting phosphor comprising a nitride-based composition represented by the chemical formula M(x/v)M'2Si5-xAlxN8:RE, wherein: M is at least one unit price having a valence v, a valence or a trivalent metal; M' is at least one of Mg, Ca, Sr, Ba, and Zn; and RE is at least one of Eu, Ce, Tb, Pr, and Mn; wherein x satisfies 0.1 ≦ x < 0.4 And wherein the phosphor has a general crystalline structure M'2Si5N8:RE, Al replaces Si in the crystalline structure, and M is substantially located at the interstitial site. In addition, the phosphorescent system is configured such that the deviations CIE Δx and Δy of the chromaticity coordinates produced by aging for 1,000 hours at 85 ° C and 85% humidity are less than about 0.03. In addition, the phosphor absorbs UV and blue radiation and emits light having a photoluminescence peak wavelength in the range of about 620 nm to 650 nm. |