Effect of Li+ ions doping on structure and luminescence of (Y,Gd)BO3:Tb3+

The (Y,Gd)BO3:Tb3+ and Li+-doped (Y,Gd)BO3:Tb3+ phosphors were prepared by high temperature solid-state method. The inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the excitation and emission spectra were used to characterize the samples. The results of ICP-AES and XRD indicated that Li+ ions could enter the (Y,Gd)BO3:Tb3+ lattice and induce the lattice expansion. It could be seen from SEM that the particles were spherical and non-aggregated when Li+-ions were doped into (Y,Gd)BO3:Tb3+ phosphor. With the incorporation of Li+ ions into (Y,Gd)BO3:Tb3+, the excitation intensity of (Y,Gd)BO3:Tb3+ was found to increase and, thus, the emission intensity of (Y,Gd)BO3:Tb3+ increases. The optimal Li+ doping concentration of ions was found to be 0.025 mol per formula unit, which was also found to induce concentration quenching due to the increase in Tb3+ content from 10 mol.% to 12 mol.%.