US Patent 9287469 Encapsulation for phosphor-converted white light emitting diode

An improved light emitting device, especially a phosphor-converted white light device, wherein the light extraction efficiency and the color temperature distribution uniformity are improved by the introduction of both nanoparticles and light scattering particles proximate to the light source. Nanoparticles having a high index of refraction are dispersed throughout a wavelength conversion layer to adjust the index of refraction of the layer for improved light extraction. Light scattering particles may be dispersed in the wavelength conversion layer and/or in a surrounding medium to improve the spatial correlated color temperature uniformity.