Generation of white-light from Dy3+ doped Sr2SiO4 phosphor

A single host lattice white light emitting Sr2SiO4:Dy3+ powder phosphor was synthesized by solid state reaction process using a temperature of 1000 °C. The structure, particle morphology, chemical composition and oxidation states, photoluminescence (PL) and decay properties of the phosphor were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and PL spectroscopy, respectively. The objective of this study was to prepare a phosphor that can be used in white light emitting diodes. The XRD patterns showed a monoclinic structure of Sr2SiO4 with minor incidental secondary phases from unreacted precursors. An agglomeration of particles with irregular shapes was observed from the SEM micrographs. The PL emission spectra of the Sr2SiO4:Dy3+ phosphor excited at 350 nm consist of blue, yellow and red line emissions at 486 nm, 575 nm and 668 nm corresponding respectively to the (4F9/2→6H15/2), (4F9/2→6H13/2) and (4F9/2→6H11/2) transitions of Dy3+. The combination of these emissions constituted white light as indicated on the Commission Internationale de L'Eclairage chromatic coordinate diagram. The decay characteristics show that the phosphor consists of a single exponential decay process.