Sol-gel preparation and luminescent properties of Li2.06Nb0.18Ti0.76O3:Eu3+ red phosphor

Li2.06Nb0.18Ti0.76O3: xEu3+ (x = 1–4 wt%) phosphors were synthesized by sol-gel method. The effects of the synthesis temperature, holding time and concentration of Eu3+ on the luminescent properties were detailed investigated. The properties of the samples were characterized by X-ray powder diffraction (XRD) and photoluminescence spectroscopy. X-ray powder diffraction showed that the samples were composed of Li2TiO3 and EuNbO4 when sintered at 850 °C for 9 h. With the increasing of Eu3+ concentration, holding time and synthetic temperature, both the intensities of excitation spectra (monitored at 612 nm) and emission spectra (excited at 396 nm) of Eu3+ were firstly remarkably enhanced and then weakened. When the content of Eu3+ increased to x = 3 wt% at 850 °C for 9 h, the intensity of peak reached the maximum. The emission spectra and chromaticity coordinate (CIE) demonstrated that the Li2.06Nb0.18Ti0.76O3: 3 wt% Eu3+ red phosphors were better than the commercial red phosphors Y2O3: Eu3+. These features show that the red phosphors can be used as suitable candidates for LEDs.