Silicon dioxide ultraviolet to visible phosphors material

摘要

The present work include preparation of phosphors materials from rare earth (Eu) ion doping Silicon Oxide (SiO_2), and study the characteristics of phosphors for ultraviolet to visible conversion. The phosphor materials have been synthesized by two steps, the first was preparing the powder by solid state method usingSiO_2, and Eu_2O_3 with doping concentration of 5% and different calcination temperature (1000, 1200 and 1400℃), the second step is the preparing of the colloid by dispersing the produced powder in a polyvinyl alcohol solution (4%). Powder preparation achieved by mixing the powder according to weight percentage, milling then calcinning the mixture at the above temperatures. The produced powder was characterized by X-Ray diffraction. The X-Ray resultsshow a mismatch with the standard peaks. The difference may be due to the variation in purity of the materials and the phases before calcination. Colloid preparation achieved by dissolving the PVA in water (4%) then dispersing the powder into the solution by using the hot plate magnetic stirrer and ultrasonic bath. The produced powder was characterized by using Fourier transform infrared (FTIR) and Photoluminescence spectra (PL). The results of photoluminescence spectra show that samples doped with Europium ions emit red color with wave length 612nm.The intensity of emission was increased with increasing calcination temperature.