Synthesis and photoluminescent properties of cuboid-like Y2(C2O4)3:Tb3+ green-emitting phosphors

• Y2(C2O4)3:Tb3+ phosphor was prepared by complexing-agent-assisted hydrothermal method.
• pH, surfactant and the luminescence of the Y2−x(C2O4)3:xTb3+ phosphors were discussed.
• x = 1.4, the phosphor obtained in pH 1.5 and CA has the highest luminescent intensity.
• Quadrupole-quadrupole interaction plays the major role in concentration quenching.

In this paper, the Tb3+-doped Y2(C2O4)3 phosphors were prepared using the hydrothermal method in the presence of surfactants. XRD, SEM and fluorescence spectroscopy were used to study the structure and luminescence properties of the material. The effects of surfactants and pH values on the morphologies and photoluminescent properties of Y2(C2O4)3:Tb3+ phosphors were investigated, respectively. When surfactant CA (Citric Acid) and pH 1.5 were employed, homogeneous cuboid-like structure phosphor was obtained, and it was composed of a small number of homogeneous particles with sizes of 2–4 μm and showed higher luminescent intensity than phosphors prepared with surfactants EDTA, Glycine and PEG. Under the 370 nm radiation excitation, Y2−x(C2O4)3:xTb3+ phosphors exhibit green emission (546 nm) corresponding to the 5D4 → 7F5 transition of Tb3+. The emission intensity of this phosphor can be influenced by Tb3+ doping concentration and the maximum intensity of luminescence is observed at the Tb3+ concentration around x = 1.4. The corresponding concentration quenching mechanism is verified as quadrupole–quadrupole interaction. The CIE chromaticity coordinates values of Y0.6 (C2O4)3:1.4Tb3+ almost locate in the green region.