Structural and photoluminescence studies of lithium calcium silicate phosphor doped with Eu3+ ion for LED application

Li2CaSiO4:Eu3+ phosphors with single phase were successfully synthesized by the solid state reaction method. Characterizations XRD, SEM, FTIR, Photoluminescence and CIE were studied of the prepared samples. SEM images showed irregular, non-homogeneous morphology and relatively big grain size of the samples. From the FTIR, it was observed that most of the bands are due to ligand ions (Ca-O, Si-O, Li-O) stretching or bending vibrations. The authors are interested in investigating the concentration effect of the activator ion in the host and also in the effect of the excitation wavelength on emission intensity of the synthesized phosphors. The experimental results of Li2CaSiO4:Eu3+ showed the different excitation wavelengths in the range 200-500 nm, especially in the ultraviolet region. Strong and sharp excitation peak was observed at 394 nm. The emission in the red spectrum and the CIE Chromaticity coordinate (0.68, 0.31) indicated that the phosphor has great potential in UV chip pumped white LEDs. A comparative investigation of the excitation and emission intensities of Li2CaSiO4:Eu3+ were studied. The CIE study of Li2CaSiO4:Eu3+ under the excitation of 394 nm was also studied. The CIE Chromaticity coordinates (0.68, 0.31) and (0.60, 0.39), (0.60, 0.38) indicated orange/red color. They are useful for the generation of white light for ultra-violet (394 nm) chip when pumped and multi-phosphors are converted into white LEDs.