WAVELENGTH CONVERTER AND LIGHT-EMITTING DEVICE HAVING SAME

摘要

An alumina-based ceramic wavelength converter is described having a surface layer containing a second phase of alumina, preferably as alumina crystallites. The surface layer is formed as a result of the sintering process used to form the bulk ceramic which is itself substantially transparent. The ceramic wavelength converter is combined with a light emitting diode to form a light emitting device. Preferably, the ceramic wavelength converter is comprised of an alumina-based phosphor represented by a general formula A3B5O12:Ce, wherein A is Y, Sc, La, Gd, Lu, or Tb and B is Al, Ga or Sc.

主权项

1. A wavelength converter comprising a solid monolithic piece of a luminescent ceramic material, the ceramic material comprising an alumina-based phosphor capable of converting primary light having a first peak wavelength into secondary light having a second peak wavelength, a bulk portion of the converter being substantially transparent, and the converter having at least one major surface with an as-sintered surface layer having an alumina second phase.