Luminescence properties of orange emitting CaAl4O7:Sm3+ phosphor for solid state lighting applications

Sm3+-doped CaAl4O7 phosphor has been synthesized using the sol-gel method with a varying doping concentration of Sm3+ ions. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images were used to study the structural and morphological properties of the material. The UV-VIS-NIR spectrum was also recorded to analyze the optical transitions of CaAl4O7 phosphor doped with Sm3+ ions. The photoluminescence (PL) spectra of the phosphors were also recorded to examine the luminescence properties. The PL spectra exhibit intense orange emission at 602 nm that was obtained for the prepared samples using the 403 nm excitation. The optimized concentration of Sm3+ ions in CaAl4O7 was found to be 0.03 mol, beyond which concentration quenching was observed. The CIE color chromaticity coordinates of all the synthesized phosphors lie in the orange region of the chromaticity diagram. All of these results indicate the candidature of CaAl4O7 phosphor doped with Sm3+ ions for lighting and display applications.