Process of manufacturing a conversion element, conversion element and light emitting device comprising the conversion element
A method of manufacturing a conversion element is disclosed. A precursor material is selected from one or more of lutetium, aluminum and a rare-earth element. The precursor material is mixed with a binder and a solvent to obtain a slurry. A green body is formed from the slurry and the green body is sintered to obtain the conversion element. The sintering is performed at a temperature of more than 1720° C.
1. A method of manufacturing a conversion element, the method comprising:
providing a precursor material, the precursor material comprising a material selected from the group consisting of lutetium, aluminum and a rare-earth element,
mixing the precursor material with a binder and a solvent to obtain a slurry;
forming a green body from the slurry;
sintering the green body to obtain the conversion element, wherein the sintering is performed at a temperature of more than 1720° C.; and
structuring a surface of the green body prior to sintering the green body.
2. The method according to claim 1 , wherein sintering is performed at a temperature of less than 1780° C.
3. The method according to claim 1 , wherein providing the precursor material comprises providing a first precursor material comprising the lutetium, a second precursor material comprising the aluminum and a third precursor material comprising the rare-earth element.
4. The method according to claim 3 , wherein the first precursor material is Lu 2 O 3 , the second precursor material is Al 2 O 3 and the third precursor material is CeO 2 .
5. The method according to claim 1 , wherein mixing the precursor material with the binder and the solvent comprises ball milling.
6. The method according to claim 1 , wherein the green body comprises a green tape and the green tape is formed from the slurry via tape casting.
7. The method according to claim 1 , wherein the structuring comprises forming grooves with a depth between 10 μm and 40 μm.
8. The method according to claim 1 , wherein after providing the precursor material no further material comprising aluminum is added.
9. The conversion element made according the method of claim 1 , wherein the conversion element comprises a first phase and a second phase, and wherein the first phase comprises the lutetium, the aluminum, oxygen and the rare-earth element and the second phase comprises Al 2 O 3 single crystals.
10. A conversion element comprising:
a first phase and a second phase,
wherein the first phase comprises lutetium, aluminum, oxygen and a rare-earth element,
wherein the second phase comprises Al 2 O 3 single crystals, and
wherein a surface of the conversion element comprises a plurality of structures,
wherein each of the structures is laterally completely surrounded by grooves, and
wherein the Al 2 O 3 single crystals at least partly protrude from the plurality of structures.
11. The conversion element according to claim 10 , wherein the first phase comprises Lu 3 Al 5 O 12 :Ce.
12. The conversion element according to claim 10 , wherein the Al 2 O 3 single crystals are hexagonal single crystals.
13. The conversion element according to claim 10 , wherein the Al 2 O 3 single crystals have an average crystal size between 1 μm and 10 μm.
14. The conversion element according to claim 10 , wherein each groove has a depth of between 10 μm and 40 μm.
15. A light emitting device comprising:
a primary light source configured to emit primary radiation during operation of the light emitting device; and
a conversion element arranged in a beam path of the primary light source and configured to at least partly convert the primary radiation into secondary radiation,
wherein the conversion element comprises a first phase and a second phase,
wherein the first phase comprises lutetium, aluminum, oxygen and a rare-earth element and the second phase comprises Al 2 O 3 single crystals, and
wherein a surface of the conversion element comprises a plurality of structures,
wherein each of the structures is laterally completely surrounded by grooves, and
wherein the Al 2 O 3 single crystals at least partly protrude from the plurality of structures.
16. The light emitting device according to claim 15 , wherein the light emitting device is a light emitting diode.
17. The light emitting device according to claim 15 , wherein each groove has a depth of between 10 μm and 40 μm.
18. The conversion element according to claim 10 , wherein the plurality of structures extends into the first phase.
19. The light emitting device according to claim 15 , wherein the light emitting device is a laser device.