Synthesis and luminescent properties of two different Y2WO6:Eu3+ phosphor phases

In this paper, two different Y2−xEuxWO6 phases were synthesized. The monoclinic phase was prepared via a conventional solid-state reaction, whereas the orthorhombic phase was obtained via a facile, low-temperature combustion synthesis method. X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and photoluminescence (PL) spectroscopy were used to characterize the resulting phosphors. The XRD results indicate the orthorhombic phase crystallized isostructurally with the Aurivillius Bi2WO6 phase, whereas the other polymorph crystallized isostructurally with Yb2WO6 in the monoclinic system. The SEM studies revealed both phases had a strong tendency to form agglomerates averaging nanometers in size. The photoluminescence emission spectra confirmed all of the samples were efficiently excited by near UV light and were dominated by the electric dipole transition 5D0 → 7F2. The orthorhombic Y2−xEuxWO6 excitation spectrum possessed a broad band across the entire UV region (220-400 nm); therefore, Y1.86Eu0.14WO6 could be considered an efficient spectral converter material for use in dye-sensitized solar cells.