Control of chromaticity by phosphor in glasses with low temperature sintered silicate glasses for LED applications

Abstract

Phosphor-in-glass (PiG) color converters for LED applications were fabricated with a mixture of phosphors, Y3Al5O12:Ce3+ (yellow) and CaAlSiN3:Eu2+ (red). The low sintering temperature (550 degrees C) of SiO2-Na2O-RO (R = Ba, Zn) glass powder enabled the inclusion of CaAlSiN3:Eu2+ (red) phosphor which cannot be embedded with conventional glass powders for PiGs. By simply varying the mixing ratio of glass to phosphors as well as the ratio of yellow to red phosphors, the facile control of the CIE chromaticity coordinates and correlated color temperature of the LED following the Planckian locus has been achieved. Phosphors were well distributed within the glass matrix without noticeable reactions, preserving the enhanced thermal quenching property of the PiG compared to those with silicone resins, for LEDs.