| abstract |
A red-emitting phosphor comprises a nitride-based composition represented by the chemical formula M (x/v) M′ 2 Si 5-x Al x N 8 :RE, wherein: M is at least one monovalent, divalent or trivalent metal with valence v; 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 the general crystalline structure M′ 2 Si 5 N 8 :RE, Al substitutes for Si within the crystalline structure, and M is located substantially at interstitial sites. Furthermore, the phosphor is configured such that 1,000 hours of aging at 85° C. and 85% humidity results in a deviation in chromaticity coordinates CIE Δx and Δy of less than about 0.03. Furthermore, the phosphor absorbs radiation in the UV and blue and emits light with a photoluminescence peak wavelength within the range from about 620 to 650 nm. |