Synthesis and luminescence properties of Ce3+ doped MWO4 (M=Ca, Sr and Ba) microcrystalline phosphors

The Ce3+ doped and undoped samples of alkali earth metal tungstate MWO4 (M=Ca, Sr, and Ba) phosphors are synthesized by a co-precipitation method in controlled pH environment. The resulting phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), photoluminescence (PL) and thermoluminescence (TL). XRD pattern and SEM micrographs reveal the formation of agglomerated microcrystalline phosphor. FTIR spectra show the strong absorption around 821 cm−1 due to characteristic vibrations of (WO4)2− complex. PL excitation spectra show broadband in the UV region having peak at 280 nm, and the emission spectrum shows broadband in the visible region with peak in the blue region. The PL emission intensity increases with Ce3+ concentration with the most effective concentration at 5 mol%. The complex TL glow curve of Ce3+ doped phosphors is deconvoluted by using a TLAnal computer program. The trap parameters obtained by TLAnal were compared with those calculated by Chen׳s method and a possible model for TL is discussed.