Sol–gel synthesis and luminescence properties of CaGd2(MoO4)4:Pr3+ phosphors for white LED applications

Abstract

A series of novel red emitting CaGd2(MoO4)4:xPr3+ (x = 0.005–0.045) micro phosphors were successfully prepared via a simple citrate assisted sol–gel method-ray powder diffraction, scanning electron microscope, photoluminescence spectra and decay life time measurement were utilized to study the properties of CaGd2(MoO4)4:xPr3+ phosphors well crystallized, fine and homogenous micro particles appeared at the heat treatment at 900 °C for 6 h. The results confirms that CaGd2(MoO4)4 host has tetragonally distorted scheelite structure with space group I41/a. Under the excitation wavelength of 449 nm Pr3+ activated CaGd2(MoO4)4 phosphor shows the red emission peaked at about 649 nm, which is attributed to 3P0–3F2 transition of Pr3+ ions. The CIE co-ordinates of CaGd2(MoO4)4:0.035Pr3+ phosphor are x = 0.702 and y = 0.289, which are evidently close to the standard NSTC value. The luminescence properties of as prepared phosphors indicates that CaGd2(MoO4)4:xPr3+ phosphor may be a potential red emitting material for W-LED applications.