| abstract |
The invention is concerned with 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 an oxido-nitrido-silicate of general formula EA 2-z Si 5-a B a N 8-a O a :Ln a , wherein 0<z≦1 and 0<a<5. comprising at least one element EA selected from the group consisting of Mg, Ca, Sr, Ba and Zn and at least one element B selected from the group consisting of Al, Ga and In, and being activated by a lanthanide selected from the group consisting of cerium, europium, terbium, praseodyrnium and mixtures thereof. The invention is also concerned with a phosphor, which is an oxido-nitrido-silicate of general formula EA 2-z Si 5-a B a N 8-a O a :Ln z , wherein 0 |