Effects of doping Pr$^{3+}$ and Gd$^{3+}$ into YAG:Ce phosphors on the luminescence properties

摘要

A series of (Y$_{0.98a??xa??y}$Ce$_{0.02}$Pr$_x$Gd$_y$)$_3$Al$_5$O$_{12}$ ($x = 0a??0.02$, $y = 0, 0.3$) phosphors were prepared by amodified co-precipitation method. The phases, luminescence properties, effect of calcination temperature on luminescenceproperties and energy transfer (ET) were investigated.The results indicated that the doping of Pr$^{3+} and Gd$^{3+}$ in all samples did not produce any new phases but caused a slight lattice expansion. The series of (Y$_{0.98a??x}$Ce$_{0.02}$Pr$_x$)$_3$Al$_5$O$_{12}$ phosphors emitadditional red light at 612 nm, and when $x = 0.005$, the red/yellow ratio of the emission spectrum is the largest. Compared with the (Y$_{0.975}$Ce$_{0.02}$Pr$_{0.005}$)$_3$Al$_5$O$_{12}$ phosphor, continued doping 30 at% Gd$^{3+}$ in the (Y$_{0.675}$Ce$_{0.02}$Pr$_{0.005}$Gd$_{0.3}$)$_3$Al$_5$O$_{12}$ sample makes the peak wavelength of yellow light emission shift from 533 to 561 nm. Doping Pr$^{3+}$ and Gd$^{3+}$ results in the decrease of integrated emission intensity, but the emission intensity and the red/yellow ratio can be increased by raising the calcination temperature. In addition, there is only the ET from Ce$^{3+}$ to Pr$^{3+}$ in the (Y$_{0.675}$Ce$_{0.02}$Pr$_{0.005}$Gd$_{0.3}$)$_3$Al$_5$O$_{12}$ sample.