The effect of ligand-to-Eu³⁺ charge-transfer transitions (LMCT) on the photoluminescence intensity of M₂SiO₄: Eu³⁺ (M = Ca, Zn) type phosphors

In this study, silicate systems, M₂SiO₄ (M = Ca, Zn) were produced by solid state reaction and doped with 1 mol% Eu³⁺ rare-earth ion. Their heat treatments, which were conducted at 1200 °C and above for minimum 3 hours under an open atmosphere, were applied according to the DTA/TG results. Powder X-ray diffraction XRD analyses were performed to determine the phase properties of the phosphor systems after the sintering process. It was proved that the structures of two of the phosphor systems were well formed in except that the Zn₂SiO₄ had some ZnO secondary phases. The expected photoluminescence (PL) results were presented and the transitions of the Eu³⁺ ions were observed for both phosphors.