Lumileds LLC

Koninklijke Philips Corporation N.v.

Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Philips Lumileds Lighting Company LLC

Koninklijke Philips Electronics N.v.

Philips Koninklijke N.v.

Theo Arnold Kop

Jan De Graaf

Michael Ragan Krames

Peter Josef Schmidt

Hans-Helmut Bechtel

Gerd O Mueller

Regina B Mueller-Mach

Joerg Meyer

Marcus Antonius Verschuuren

Céline Catherine Sarah Nicole

Johan Marra

Michel Paul Barbara Van Bruggen

Andreas Krell

Ronald Martin Wolf

Rolf Theo Anton Apetz

Thomas Hutzler

Hans Van Sprang

Michel P B Van Bruggen

Jan De Graff

Rolf T A Apetz

A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Luminescent ceramic for a light emitting device

The invention relates to a phosphor in a polycrystalline ceramic structure and a light-emitting element provided with the same comprising a Light-Emitting Diode (LED) in which a composite structure of phosphor particles is embedded in a matrix, characterized in that the matrix is a ceramic composite structure comprising a polycrystalline ceramic alumina material, hereafter called luminescent ceramic matrix composite. This luminescent ceramic matrix composite can be made by the steps of converting a powder mixture of ceramic phosphor particles and alumina particles into a slurry, shaping the slurry into a compact, and applying a thermal treatment, optionally in combination with hot isostatic pressing into a polycrystalline phosphor-containing ceramic alumina composite structure. The luminescent ceramic matrix composite further allows a method of tuning the light-diffusing properties by changing at least one of the fractions of phosphor particles and second ceramic particles, the grain size of the particles of the ceramic composite structure, the difference in the refractive index of the particles of the ceramic composite structure, and the porosity in the polycrystalline phosphor-containing ceramic composite structure.

Phosphor in polycrystalline ceramic structure and a light-emitting element comprisng same

Phosphor in polycrystalline ceramic structure and a light-emitting element comprising same

A cooling device for cooling a light-emitting semiconductor device, such as a LED device (), comprises a ceramic plate () having coolant-conveying channels () incorporated therein. The ceramic plate () is adapted for forming an integral part of the optical system of the light-emitting semiconductor device () and to cool a light-emitting portion () of the light-emitting semiconductor device (). A method of forming a cooling device comprises the steps of forming a charge of ceramic particles, embossing the charge with a stamp to form coolant-conveying channels in the charge, hardening the charge, and providing a cover on top of the channels to seal them.

Cooling device for a light-emitting semiconductor device and a method of manufacturing such a cooling device

The present invention relates to highly dense translucent and transparent aluminium oxide components for applications, e.g. in the lighting industry, where a fine crystal size has to be obtained and stabilized for use at temperatures of 800&#xb0; C. or more. Disclosed are high-strength polycrystalline alumina products which include 0.001-0.5 weight-% ZrOstabilizing a fine crystal size &#x3c;2 &#x3bc;m or, preferably, &#x3c;1 &#x3bc;m if used at temperatures of 800&#xb0; C. or more. The microstructure exhibits an extremely high relative density enabling a high real in-line transmission &#x3e;30% measured over an angular aperture of at most 0.5&#xb0; at a sample thickness of 0.8 mm and with a monochromatic wavelength of light &#x3bb;, preferably, of 645 nm.

Transparent polycrystalline aluminium oxide

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Eindhoven, Netherlands

Theo Arnold Kop