Synthesis and photoluminescence properties of ZnTiO3:Eu3+ red phosphors via sol-gel method

ZnTiO3:Eu3+ phosphors were synthesized with different concentrations of Eu3+ doping through sol-gel method. The samples were calcined at different temperatures for 2 h in air. The synthesized powders were characterized by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Raman and photoluminescence spectroscopy. The XRD results showed that the ZnTiO3:Eu3+ phosphors doped with different concentrations of Eu3+ ions calcined at 600 degrees C were of single phase, which indicated that the Eu3+ ions had been successfully incorporated into the ZnTiO3 host lattice and did not destroy the lattice structure of ZnTiO3 host. The Raman spectrum, SEM and TEM also proved that the doping of Eu3+ did not change the lattice structure of hexagonal ZnTiO3 host. The photoluminescence (PL) of Eu3+ ions with the main emission peak at 614 nm was observed to increase with Eu3+ concentrations from 0.5 mol.% to 2.0 mol.% and decreased when the concentration was increased to 2.5 mol.%. The decrease in the PL intensity at higher Eu3+ concentrations could be associated with concentration quenching effect. The CIE1931 chromaticity diagram (x, y) of ZnTiO3:2.0 wt.% Eu3+ phosphors were located in the red region (x = 0.652, y = 0.347). The luminescence properties suggested that ZnTiO3:Eu3+ phosphors might be regarded as a potential red phosphor candidate for light emitting diodes (LEDs).