Near White Emitting Host Sensitized Dy3+ doped GdPO4 Nanoparticles: Luminescence Studies

Host sensitized GdPO4 nanoparticles doped with Dy3+ ions have been prepared by co-precipitation method with ethylene glycol as capping agent as well as solvent. The as-prepared samples exhibit crystalline monoclinic phase of GdPO4. From the luminescence study, 4F9/2→6H15/2 of Dy3+ is dominant over 4F9/2→6H13/2 transition indicating the occupation of inversion symmetry by Dy3+ ions in the host lattice. The steady state luminescence shows effective energy transfer from gadolinium (Gd3+) to dysprosium (Dy3+) ions in the doped samples with optimum emission of Dy3+ (2 at.%) doped sample. Decay lifetime values also decrease upon increasing Dy3+ ion concentration on account of cross-relaxation concentration quenching effect. The emission colour of single phase as-prepared Dy3+ doped GdPO4 nanoparticles can be tuned from blue-violet to near white light by changing the excitation wavelength. Tunability of the light and white light emission are supported by Commission Internationale de l’Eclairage (CIE) chromaticity.