Synthesis and luminescence properties of YPO4:Dy3+, Ca2+ microsphere phosphors

• Spherical Y0.99−xCaxPO4:0.01Dy3+ phosphors were synthesized.
• The luminescence intensity of YPO4:0.01Dy3+ was significantly enhanced by doping an appropriate amount of Ca2+.
• The luminescence color of Y0.99−xCaxPO4:0.01Dy3+ phosphors was stable.

Y0.99−xCaxPO4:0.01Dy3+ (0≤x≤0.08) phosphors were synthesized by the homogeneous precipitation method. The obtained phosphors have pure tetragonal structure and spherical morphology with the particle size of about 2–3 μm. The excitation spectra present three strong excitation peaks at 325 nm, 351 nm and 365 nm in ultraviolet region owing to the f–f transition within 4f9 electron configuration of Dy3+. The emission spectra show a strong blue emission (482 nm) and another weak yellow emission (572 nm) corresponding to the 4F9/2→6H15/2 transition and the 4F9/2→6H13/2 transition of Dy3+, respectively. The luminescence intensity of YPO4:0.01Dy3+ is improved after partially substituting Ca2+ for Y3+; the emission intensity of Y0.95Ca0.04PO4:0.01Dy3+ is about 174% higher than YPO4:0.01Dy3+. Besides, the color chromaticity coordinates of the as-synthesized phosphors are within a small range of x=0.307−0.319, y=0.331−0.334.