Luminescence study of Dy³⁺ doped magnesium aluminate phosphors for white light

Abstract

Pure MgAl2O4 and a series of Dysprosium (Dy3+) doping in MgAl2O4 nanoparticles has synthesized using wet chemical sol‐gel method and prepared samples were sintered at 1100 °C. X‐ray diffraction analysis confirms the cubic phase of MgAl2O4 spinel without any impurity in phase even with different doping concentrations of Dy3+ (0.2–1.8 mol %). Under ultraviolet irradiation (283 nm) the fluorescence spectrum of pure MgAl2O4 shows maximum emission in the green‐yellow region. On Dy3+ doping in MgAl2O4, broad emission spectra have been observed due to energy transition that takes place between the host and dopant. To explore the nanophosphor for white light, chromaticity coordinates (CIE), color temperature (CCT), color rendering index (CRI) and color purity were analyzed and at 1.4 mol % doping concentration of Dy3+ in MgAl2O4 got best results i. e. CIE co‐ordinates (0.3326, 0.3334), CCT (5487), CRI (95) and minimum value of color purity (0.20 %). It is observed that emission shifts from yellow‐green to nearly white light emission as the doping is incorporated into the host. It is found that the prepared nanophosphors are energy efficient white light material.