Lutetium aluminum garnet(LuAG) precursors doped with different Pr3+ concentration(0.25at.%,0.5at.%,1.0at.%,3.0at.%,5.0at.%) were synthesized via a co-precipitation method using ammonium hydrogen carbonate as precipitant. The phase evolution and morphology of the precursor were characterized with X-ray diffractometer(XRD) and transmission electron microscopy(TEM) . The resultant LuAG:Pr3+ powder was sintered into translucent ceramic without any additives in vacuum at 1150 °C and then in nitrogen atmosphere at 1700 °C. Photoluminescence spectra of LuAG:Pr3+ powder and ceramic were measured at room temperature in vacuum ultraviolet(VUV) and ultraviolet(VU) region. For the 5d-4f transition of Pr3+ ions,dominant emission of ceramic samples peaking round 311 nm had higher luminescence intensity. And the host absorption in ceramic samples was not as intensive as that in powder samples. The luminescent intensity of LuAG:Pr3+ varied with the Pr3+ contents and the quenching concentration was about 1.0at.% for ceramic and 3.0at.% for powder,which was much higher than 0.24at.% for LuAG:Pr3+ single crystals. This phenomenon showed that the ceramic had some superiority over single crystals.
Rare earth ions doped gadolinium oxybromide phosphors GdOBr:RE3+ (RE=Eu, Tb, Ce) were synthesized by the method of solid-state reaction at high temperature, and the VUV-VIS spectroscopic properties of the phosphors were systematically investigated. Under the excitation of VUV or UV source, the phosphors doped with Eu3+ and Tb3+ show a bright and sharp emission at around 620 nm corresponding to the forced electric dipole 5D0→7F2 transition of Eu3+, and at around 544 nm corresponding to the 5D4→7F5 transition of Tb3+, respectively. For GdOBr:Ce3+, a broader and intense emission spanned 370-500 nm corresponding to the d-f transition of Ce3+ was observed. The excitation spectra were also analyzed.
