Mineral Ltd. has developed a highly efficient single crystal converter, which could convert a blue light toa white one. The feature of development is the increase in light output observed in the case of stoichiometric excess of alumina in yttrium aluminum garnet (Y3Al5O12) doped with cerium. It has been found that the addition of alumina into the melt allows to reduce the content of cerium oxide, which allows to grow the solid solution bulk crystals without the risk of crackingwhile maintaining a high photoluminescence values.
The designed converter has a thermal conductivity up to 50 times higher than the traditional powder converters, which cannot be used to generate the light beams with a high energy density (more than 1 W/mm²) due to the degradation of the polymer binders at elevated temperatures. Lightfluxofhighenergydensityis usedinprojectors, floodlight projectors, automobile headlights etc.
The designed converter has a high adaptability to manufacture because the standard equipment used to fabricate solar silicon wafers may be applied in the production process. Mineral Ltd. can grow the yttrium aluminum garnet solid solutions by Czochralski, Kyropoulos, and Stockbarger techniques.
