Structure, surface analysis, photoluminescent properties and decay characteristics of Tb3+-Eu3+ co-activated Sr2MgSi2O7 phosphor

Abstract

Tb3+-Eu3+ co-activated Sr2MgSi2O7 powder phosphors were synthesized by a solid-state reaction method. The structure, stretching vibrations, chemical and electronic states, and photoluminescent properties were studied using X-ray powder diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Time-of-flight secondary ion mass spectrometer (TOF-SIMS) and Photoluminescence (PL) spectroscopy respectively. The XRD pattern of the Sr2MgSi2O7:Eu3+, Tb3+ phosphor resembles the standard tetragonal phase of Sr2MgSi2O7. The fitted XPS data demonstrated that there were two different Sr2+ sites in the host lattice and a site occupied by Mg+ cations which connects the Sr+ sites with the Si+ ions. The TOF-SIMS results demonstrated localization and distribution of various ions within the host lattice (Sr2MgSiO7) including the Tb3+ and Eu3+ dopants. The photoluminescence of Tb3+ single doped Sr2MgSi2O7 shown to emit blue and green emissions simultaneously with green emission more intense and the blue emission improving considerably when lower concentrations of Tb3+ were used. Only red emission was observed from the Eu3+ single doped Sr2MgSi2O7. Upon Tb3+-Eu3+ co-doping, simultaneous emissions of blue, green and red lines were observed resulting in white emission.