Illumination system comprising a radiation source and a fluorescent material

Abstract

An illumination system includes a radiation source and a fluorescent material including 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. The phosphor includes a yellow red-emitting cerium-activated carbido-nitridosilicate of general formula (RE1−z)2−aEAaSi4N6+aC1−a:Cez where 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 phosphor may include a red to yellow-emitting cerium-activated carbido-nitridosilicate of general formula (RE1−z)2−aEAa Si4N6+aC1−a:Cez where 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.