Preparation and study on the spectral properties of garnet-type Li3Gd3Te2O12:Dy3+ single-phase full-color phosphor

Novel single-phased white-light-emitting Li3Gd3Te2O12:xDy3+ (x = 0.005, 0.01, 0.02, 0.05, 0.08, 0.10, and 0.15) garnet-type tellurate phosphors were firstly synthesized. The X-ray powder diffraction analysis, photoluminescence excitation and emission spectra, thermal quenching, and decay curves were applied to investigate the phase structure, luminescence, and thermal stability properties. Under the excitation of 351 nm, the emission of Li3Gd3Te2O12:0.02Dy3+ sample centered at blue (488 nm) and yellow (580 nm), corresponding to 4F9/2-6H15/2 transition and 4F9/2-6H13/2 transition, respectively. The optimum dopant concentration of Dy3+ ions in Li3Gd3Te2O12:xDy3+ was around 2 mol%. The thermal-quenching temperature was above 500 K for Li3Gd3Te2O12:0.02Dy3+. The tunable white light and correlated color temperature can be achieved in the present Li3Gd3Te2O12:xDy3+ phosphors by adjusting the yellow to blue intensity ratio based on the concentration of Dy3+ ions. The fabricated warm white LED indicates the phosphor could be a single-component white light-emitting phosphor for UV light-emitting diodes.