ILLUMINATION SYSTEM COMPRISING HETERO- POLYOXOMETALATE

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An illumination system comprising a radiation source and a luminescent material comprising at least one first phosphor capable of absorbing a part of the radiation emitted by the radiation source and emitting radiation of a wavelength different from that of the absorbed radiation, wherein said at least one phosphor is an europium(III)-activated hetero-polyoxometallate of general formula AaREb-zMmO3m+3/2b+a-1/2xFx : Euz, wherein A is as least one alkaline metal selected from the group of lithium, sodium, potassium, rubidium and cesium, RE is at least one rare earth metal selected from the group of yttrium, lanthanum and gadolinium, M is a metal selected from the group of molybdenum and tungsten or a combination thereof and wherein 0 ≤ a ≤ 1, 1 ≤ b ≤ 3, 2 ≤ m ≤ 6, 0 ≤ x < 2 and 0.002< z < 1.0 can provide light sources having high luminosity and color-rendering, especially in conjunction with a light emitting diode as a radiation source. The red-emitting europium(III)-activated hetero-polyoxometallate phosphor is efficiently excitable by primary radiation in the near UV-to-blue range of the electromagnetic spectrum.