Effect of synthesis methods on luminescence properties of LiCaPO4:Ce phosphor for radiation dosimetry

Abstract

The polycrystalline doped and un-doped LiCaPO4 phosphors were successfully prepared via solid state diffusion [SSD] and sol–gel [SG] methods. The sol–gel method was implied to decrease the processing time and heating temperature. The prepared un-doped and doped LiCaPO4 phosphors were characterized through X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Additionally photoluminescence (PL), thermoluminescence (TL) and optically stimulated luminescence (OSL) properties were studied. The XRD patterns of prepared LiCaPO4 and LiCaPO4:Ce phosphors were well matched with the ICDD file. The average particles size of LiCaPO4 and LiCaPO4:Ce phosphors were found to be in the range 2–10μm by SSD method and 2-5μm by SG method. The excitation spectra of LiCaPO4 and LiCaPO4:Ce phosphors consist of broad band in the range 200–330nm and maximum intensity was observed at 314nm. Also emission spectra consist of broad band in range from 330–500nm and maximum intensity was observed at 369nm. With the increase of Ce3+ ions concentration, the emission spectra of LiCaPO4:Ce3+ phosphors shifted to a longer wavelength. The prepared phosphors were showed excellent TL properties under β irradiation. The OSL sensitivity of the LiCaPO4:Ce phosphor synthesized by the SSD method was the nearly same as compared with the OSL sensitivity of LiCaPO4:Ce phosphor synthesized by the SG method.