Effect of Sintering Temperature on Luminescence Properties of Color Conversion Glasses in Borosilicate Glasses

Abstract

The color conversion glass is a promising material for light emitting diodes encapsulation due to its high thermal conductivity and good thermal stability. In present study, color conversion glasses were prepared by sintering a mixture of borosilicate glass frits and a YAG phosphor at temperature from 600℃ to 900℃. The effects of sintering temperature on luminescence properties were examined. Characteristics of color conversion glasses, with respect to luminescence intensity, CIE (Commission International de I'Eclairage) chromaticity and CCT (Correlated Color Temperature) were analyzed based on luminescence excitation and emission spectra. These characteristics are dependent on sintering temperature of the color conversion glasses. The CIE coordinates shift with increase of sintering temperature. The glass, sintered at 700℃, shows the best luminescence properties. But for the glasses sintered above 850℃, their luminescence properties may be destroyed. Test results of X-ray diffraction (XRD), differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS) reveal that degradation of luminescence properties with increase of sintering temperature is ascribed to the lattice disturbance of YAG and oxidation of Ce 3+ , which is caused