Synthesis and Luminescent Characteristics of (Ca4-x-yzBaySrz)(PO4)2O:xEu2+ Phosphors as a Potential Application for White-Light Emitting Diode
A novel tunable red- to yellow- emitting phosphor,(Ca4-x-y-zBaySrz)(PO4)2O:xEu2+is reported that displays a broad emission from 500 to 800nm, and its emission can be adjusted from red to yellow by changing Ba2+ and Sr2+ doping concentration. X-ray powder diffraction analysis confirmed the phase formation. Excitation and emissionspectra, and concentration dependence of emission intensity of the phosphor were investigated. The results showed that with increasing Ba2+/Sr2+ concentration, the emission peak wavelength blue-shift from 594 to 567 nm, and the color can be tuned from red to yellow. When single- phase (Ca2.95Ba0.5Sr0.5)(PO4)2O:0.05Eu2+phosphor is pumped by a blue InGaN light-emitting diode we obtain white light with color rending index between 80.0 and 88.0 and color temperatures between 3500 and 5450 K, suggesting that this material is competitive as a color conversion material for solid state lighting.