MgO:Dy3 + nanophosphor: Self ignition route, characterization and its photoluminescence properties

Abstract

For the first time series of MgO phosphors doped with different concentrations of Dy3+ (1–9mol%) were prepared by solution combustion method using glycine as a fuel. The final products were well characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The powder X-ray diffraction patterns of the as-formed product show single cubic phase. The crystallite size estimated using Scherrer's method was found to be in the range 5–15nm and the same was confirmed by transmission electron microscopy result. Photoluminescence properties of Dy3+ (1–9mol%) doped MgO for near ultra violet excitation (325nm) was studied in order to investigate the possibility of its use in white light emitting diode applications. The emission spectra consists of intra 4f transitions of Dy3+, namely 4F9/2→6H15/2 (483nm), and 4F9/2→6H13/2 (573nm). Further, the emission at 573nm shows strong yellow emission and can be applied to the yellow emission of phosphor for the application for near ultraviolet excitation. The intensity of yellow emission was attributed to intrinsic defects, especially oxygen-vacancies, which could assist the energy transfer from the MgO host to the Dy3+ ions. The Commission International De I-Eclairage chromaticity co-ordinates were calculated from emission spectra, the values (x,y) were very close to the National Television System Committee standard value of white emission. Therefore, the present phosphor was highly useful for display applications.