Oledworks Gmbh

Philips Deutschland Gmbh

Gerardus Henricus Rietjens

Hans-Peter Loebl

Georg Friedrich Gaertner

Horst Greiner

Joanna Maria Elisabeth Baken

Johannes 't Hart

The invention relates to a light source () comprising a light generating unit () like an organic light emitting diode and an outcoupling device () for coupling light out of the light generating unit in an outcoupling direction (). The outcoupling device comprises a first region () for facing the light generating unit, a second region () having a refractive index being smaller than the refractive index of the first region, and a structured intermediate region () between the first region and the second region. The first region is optically homogenous and has a thickness in the outcoupling direction being larger than a coherence length of the light, thereby reducing generally possible wavelength dependent interference effects and, thus, a corresponding degradation of the outcoupling efficiency. The outcoupling efficiency can therefore be increased.

Light source having an outsource device

The present invention relates to a method of manufacturing a light emitting device with improved internal out-coupling by providing an intermediate layer () with a modulated surface. This is achieved by exposure of a flat glass surface () to a saturated etching fluid or by providing local changes in the chemical surface composition of the glass substrate or by depositing locally separated sub-&#x3bc;m particles. By removal of the etching fluid, either ultrafine particles () are deposited or defects are generated consisting of glass component areas of sub^m-size extension with a high sticking coefficient with respect to the species deposited later on from the gas phase. These ultrafine particles or defects induce locally different growth by different sticking coefficients, with preferential columnar cone shaped growth, leading to small bumps () on the top surface of the intermediate layer (), which are then over-coated with the layers () of the light emitting element and induce sufficient scattering by subsequent reflections.

Light emitting device with improved internal out-coupling and method of providing the same

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Stramproy, Netherlands

Gerardus Henricus Rietjens