Luminescence Properties of Phosphor (Sr1-xBax) 1.95 SiO4: 0.05Eu2+

The luminescence properties of green-yellow emitting (Sr_1-xBa_x)_1.95SiO₄:0.05Eu²⁺ (0≤x≤1) phosphors were discussed in this paper. These phosphors were synthesized through the high temperature solid-state reaction technique and characterized by X-ray diffraction. The experimental results indicated that all the major phase of prepared phosphors gradually varied from α-Sr₂SiO₄ (x=0) phase to Ba₂SiO₄ (x=1) phase, and an intermediate phase between the two phases was observed at x=0.5. The excitation spectra (λem λ_em=524 nm) and emission spectra (λex λ_ex=400 nm) showed a broad band character with peak located at 365 nm and range from 579 nm to 508 nm, respectively. With the increase of concentration of barium, the thermal stability of the phosphors increased first when x is less than 0.5, and then it decreased when x surpasses 0.5. In addition, luminescence intensity was enhanced with the barium concentration. Under the 400 nm NUV light excitation the (Sr_1-xBa_x) _1.95SiO₄:0.05Eu²⁺ phosphors have a potential application in white LED.