Illumination System Comprising a Radiation Source and a Fluorescent Material

Abstract

The invention concerns an illumination system, comprising a radiation source and a fluorescent material comprising at least one phosphor capable of absorbing a part of light emitted by the radiation source and emitting light of wavelength different from that of the absorbed light; wherein said at least one phosphor is a yellow red-emitting cerium-activated carbido-nitridosilicate of general formula (RE1−z)2−aEAaSi4N6+aC1−a:CeZ, wherein 0≦a<1, 0<z≦0.2, EA is at least one earth alkaline metal selected from the group of calcium, strontium and barium, and RE is a least one rare earth metal chosen from the group of yttrium, gadolinium and lutetium. The invention is also concerned with a red to yellow-emitting cerium 10 activated carbido-nitridosilicate of general formula (RE1−z)2−aEAaSi4N6+aC1−a:Cez wherein 0≦a<1, 0<z≦0.2, EA is at least one earth alkaline metal selected from the group of calcium, strontium and barium, and RE is a least one rare earth metal chosen from the group of yttrium, gadolinium and lutetium.

Dependencies are inferred from the claim text.