||In recent years, white light-emitting diodes (W-LEDs) have been increasingly used as lighting elements. The main packaging method of W-LEDs is to use resin as the fixed fluorescent particles. However, the heat resistance of the resin, short wavelength, Fluorescent particles vary greatly in refractive index. To replace the resin with glass W-LEDs package solves the problems.
In this experiment, the selected glass components were 49.75Bi2O3-24.875B2O3-24.875ZnO-0.5Sb2O5 (mol%), BiG and 58SiO2-27Na2O-8Al2O3-7CaO (mol%), SiG two kinds of glass composition, followed by the glass powder and CaAlSiN3: Eu2+ powder wet mixed, dry pressed to observe the reaction between the phosphor and glass before and after the change and luminescence properties.
The microstructure was observed with a scanning electron microscope (SEM), and the porosity of the sample was calculated. The energy distribution analyzer (EDS) was used to analyze the relationship between elemental distribution of glass and fluorescent particles. The crystalline phase of the sample was analyzed by X-ray diffractometer (XRD) to calculate the residual amount and rate of the phosphor powder. The luminescence intensity of glass phosphors before and after sintering was analyzed by photoluminescence spectrometer (PL). With the increase of the sintering temperature, the porosity of the glass phosphor gradually declines, and the reaction between the glass and the phosphor becomes more remarkable. The surface of the silicate phosphor produces a surface layer because the glass crystallizes, whereas the bismuthate phosphor does not produce a surface layer. After the bismuth phosphors were sintered, the luminous intensity was greater than that before sintering, and the luminous intensity of the silicate phosphors was smaller than that before sintering.