Patent ID: 8663502

Claim:
A red-emitting phosphor with a nitride-based composition comprising: an element M, wherein M is at least one of Li, Na, K, Sc, Ca, Mg, Sr, Ba and Y; an element M′, wherein M′ is at least one of Mg, Ca, Sr, Ba, and Zn; silicon; aluminum; nitrogen; and an element RE, wherein RE is at least one of Eu, Ce, Tb, Pr and Mn; wherein said red-emitting phosphor has the general crystalline structure of M′ 2 Si 5 N 8 :RE with M and Al incorporated therein, wherein M is located within said general crystalline structure substantially at the interstitial sites and Al substitutes for Si within said general crystalline structure, and wherein said red-emitting phosphor is configured such that the change in chromaticity coordinates CIE Δx and CIE Δy after 1,000 hours of aging at about 85° C. and about 85% relative humidity is less than or equal to about 0.03 for each coordinate.