The sub-micron sized YAG ： Ce phosphors were synthesized via a modified sol-gel method by peptizing nano-pesudoboehmite particulate. It is found that YAG phase from the dried gel powders appears at 1000 ℃ then the pure YAG phase exists at a relatively lower sintering temperature of 1400 ℃. The smaller sizes of phosphors in the ranges of 1 - 3 μm are obtained due to the contribution of seeding effects of nano-sized alumina particles to strengthen each step of the processes. Both the excitation and emission spectra of photoluminescence of the phosphor obtained at 1400 ℃ meet well with the spectroscopic requirements of the WLED phosphors.
Polycrystal of GdPO_(4):RE^(3+)(RE=Tb,Tm)phosphors were prepared by solid-state method.Vacuum ultraviolet excitation and emission spectrum and the energy transfer mechanism between the host and dopants of Tb^(3+)and Tm^(3+)were investigated respectively.The emission of Gd^(3+)at 313 nm was enhanced by the strong absorption of CTS of Tm^(3+)at 180 nm in GdPO_(4):Tm.It has also been concluded that the excitation of Gd^(3+)is transferred to Tb^(3+)and then emission peaks of^(5)D_(J)→^(7)F_(J)of Tb^(3+)were observed.
