Red emitting luminescent materials

Abstract

The invention relates to an improved red light emitting material of the formula M1−yA1+xSi4−xN7−x−2yOx+2y: RE whereby M is selected out of the group comprising Ba, Sr, Ca, Mg or mixtures thereof, A is selected out of the group comprising Al, Ga, B or mixtures thereof, RE is selected out of the group comprising rare earth metals, Y, La, Sc or mixtures thereof and x is ≧0 and ≦1 and y is ≧0 and ≦0.2. This material is believed to crystallize in a novel structure type that comprises two individual lattice sites for rare 10 earth metal incorporation, which leads to an improved lighting behaviour.

Dependencies are inferred from the claim text.