Blue to yellow-orange emitting phosphor, and light source having such a phosphor

1. A blue to yellow-orange emitting phosphor from the class of the orthosilicates, which substantially has the composition AE2SiO4:D, wherein the phosphor has as component AE=Sr, Ba, Ca, or Mg, alone or in combination, the activating doping D consisting of Eu and a small proportion x of AEO contained therein being replaced by REN, where RE=rare earth, so as to achieve the stoichiometry AE 2−x−a RE x Eu a SiO 4−x N x .

2. The phosphor as claimed in claim 1 , wherein RE=La or Y alone or in combination.

3. The phosphor as claimed in claim 1 , wherein the Eu content is between a =0.02 and 0.45.

4. The phosphor as claimed in claim 1 , wherein AE contains Sr and/or Ba to an amount of at least 66 mol %, in particular with a Ca content of at most 5 mol % and an Mg content of at most 30 mol %.

5. The phosphor as claimed in claim 1 , wherein the content x is between 0.3 and 2 mol %.

6. A light source having a primary radiation source, which emits radiation in the short-wave region of the optical spectral region in the wavelength range from 140 to 480 nm, this radiation being partially or completely converted into secondary radiation with a longer wavelength in the visible spectral region by means of a first phosphor as claimed in claim 1 .

7. The light source as claimed in claim 6 , wherein the primary radiation source used is a light-emitting diode based on InGaN or InGaAIP or a discharge lamp based on low pressure or high pressure, or an electroluminescent lamp.

8. The light source as claimed in claim 6 , wherein part of the primary radiation is also converted into radiation with a longer wavelength by means of further phosphors, the phosphors in particular being selected and mixed appropriately so as to generate white light.

9. The light source as claimed in claim 7 , wherein the light-emitting diode includes an indium-containing fill.

10. A process for producing a high-efficiency phosphor, comprising the steps of:

a) providing the starting materials SiO 2 and REN, AE precursors, and an Eu precursor, in a substantially stoichiometric ratio;

b) mixing the staring materials to form a mixture; and

c) annealing the mixture in an Al 2 O 3 , AIN or W or Mo crucible using a flux at approximately 1300 to 1700° C.

11. The process as claimed in claim 10 , wherein the AE precursors comprise at least one of SrCO 3 , BaCO 3 , CaCO 3 and MgO.

12. The process as claimed in claim 10 , wherein the Eu precursor is Eu 2 O 3 .

13. The process as claimed in claim 10 , wherein the flux is SrF 2 or BaF 2 .

14. The process as claimed in claim 10 , wherein the annealing is carried out at 1500-1600° C.