Luminescent performance of rare earths doped CaBi2Ta2O9 phosphor

A series of red-emitting phosphors of CaBi2Ta2O9:Pr3+ and CaBi2Ta2O9:Eu3+ were synthesized by the solid-state reaction method. The crystal structure and photoluminescence properties were investigated by X-ray diffraction (XRD) and photoluminescence spectra. The emission spectra showed that the red emission peaks were located at 622 nm for Pr3+ and 615 nm for Eu3+, respectively. The optimal doping concentrations for Ca1-xBi2Ta2O9:xPr(3+) and Ca1-yBi2Ta2O9:yEu(3+) were x=0.02 and y=0.15, respectively. The effect of fluxes (H3BO3, NH4F, CaCl2 and CaF2) and charge compensations (Li2CO3, Na2CO3 and K2CO3) on luminescent properties were investigated in detail. It was found that the relative emission intensity of Ca0.98Bi2Ta2O9:0.02Pr(3+) with 10 mol.% H3BO3 flux was about 2.9 times higher than that of the sample without flux. The relative emission intensity of Ca0.7Bi2Ta2O9:0.15Eu(3+), 0.15K(+) was about the 2.1 times higher than that of Ca0.85Bi2Ta2O9:0.15Eu(3+).