Enhancement of photoluminescence of Cd_0.95Eu_0.05SiO₃ phosphor using Na⁺ and K⁺ as charge compensators

Despite its high photoluminescence (PL) performance, cadmium silicate (CdSiO₃) as a luminescence host has not been comprehensively studied. In this article, we present a simple solution combustion method for the synthesis of Na⁺ and K⁺ co-doped Cd_0.95Eu_0.05SiO₃ phosphor. The influence of charge compensators such as Na⁺ and K⁺ on the luminescence performance of Cd_0.95Eu_0.05SiO₃ was systematically investigated. X-ray diffraction results confirms that Cd_0.95Eu_0.05SiO₃:Na⁺ and Cd_0.95Eu_0.05SiO₃: K⁺ phosphors are in monoclinic phase and found to increase in the crystallinity as concentration of Na⁺ and K⁺ increases. Scanning electron microscope images exhibit agglomerated particles having nanoscale dimension. PL excitation spectra of Cd_0.95Eu_0.05SiO₃, Cd_0.95Eu_0.05SiO₃:Na⁺ and Cd_0.95Eu_0.05SiO₃:K⁺ phosphors exhibit excitation peaks in the ultra-violet (UV), near-UV and far-UV regions. Very interestingly, the intensity of PL emission was found to increase with increase in the Na⁺ and K⁺ concentrations. The optimum co-dopant concentrations were found to be 7 mol% for both phosphors. The emission intensity of 613 nm peak was enhanced by a factor of 1.78 and 1.66 with Na⁺ and K⁺ co-doping respectively. The enhancement in PL emission has been explained by the mechanism of charge compensation and phosphor crystallinity. The PL results confirms that these phosphors could be potential materials for optoelectronic applications.