摻雜Eu2+之Ca8Mg(SiO4)4Cl2螢光體的製備與其光激發光特性之研究

Abstract

The research is attempted to investigate the green color photoluminescence of Ca8Mg(SiO4)4Cl2 doped Eu2+ ion that are synthesized by solid state method. The interaction exchange between six 4f electrons and 5d electron of Eu2+ becomes very weak as a stronger covanlency of host lattice. This weak interaction of 4f electrons and 5d electron makes the 7Fj splitting 4f6 configuration well was resolved in excitation spectra at room temperature. The main emission peaking at 505nm is due to 4f-5d transition of Eu2+ as this phosphor was excited by blue light at 395nm, which is in good agreement with the calculated value 505nm with the relation E = Q[1-(V/4)1/v 10-(n•ea•r)/8], and implied that luminescence center Eu2+ occupied the octa-coordinated Ca2+ site in host lattice. For high luminescence efficiency, it is essential to adjust the firing condition and activator concentrations. Here, firing condition can not affect the ground state 8S7/2 to the crystal field split eg(4f65d) state, the emission wavelength and the shape of emission spectra would not be influenced with it. However, the variation of the crystallization and the particle size under different firing condition would be observed distinctly by XRD and Laser particle size analysis, the luminescence efficiency could follow the above result. In addition, the intensity of emission spectrum would trend to increase when the molar fraction of Eu2+ was enhanced from 0.024 to 0.16. Finally, the relation of firing condition and the powder property would be studied and discussed by SEM in this report.