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US 2004/0166320 A1Published application
Coated phosphor, light-emitting device having such a phosphor, and a method for producing it
AssigneeOSRAM Opto Semiconductors GmbH
InventorManfred Kobusch
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Abstract
Coated phosphor comprising a powder, formed by particles, of a phosphor, the phosphor particles being coated with a vitreous material, the vitreous material being silicate glass. The production is preferably performed by condensation of organosilanol.
Claims6
A coated phosphor comprising a powder, formed by particles, of a phosphor, the phosphor particles being coated with a vitreous material, wherein the vitreous material is silicate glass.
A method for producing a coated phosphor, with the following method steps:
- a) introducing uncoated phosphor powder and organosilanol, in particular alkylsilicic acid, into organic solvents, in particular ethanol;
- b) boiling down the solution to evaporate the highly volatile components at a low temperature T1 in the range of 30 to 55° C.;
- c) distilling off the high-boiling components until vitrified aggregates are produced at a higher temperature T2 in the range of 55 to 120° C.;
- d) drying the powder;
- and
- e) condensing the coating to form silicate glass at an even higher temperature T3 in the range of 250 to 350° C.
3 more elements
Dependencies are inferred from the claim text.