Effect of RE3+concentration in Cd3SiO5 luminescence

Cadmium oxyorthosilicate (Cd₃SiO₅) is a promising host for luminescent materials, but its optical properties remain poorly explored because of the difficulty in obtaining it as a single pure phase. In this work, single-phase Cd₃SiO₅ was synthesized by a sol-gel method and doped with 0.5, 1, and 3 mol% of Pr³⁺, Tb³⁺, and Eu³⁺. Phase purity was confirmed by X-ray diffraction, while FTIR and Raman spectroscopy verified the successful incorporation of the rare-earth ions without altering the crystal structure. Photoluminescence measurements revealed the characteristic emissions of Eu³⁺ (613 nm, ⁵D₀→⁷F₂), Pr³⁺ (610 nm, ¹D₂→³H₄), and Tb³⁺ (559 nm, ⁵D₄→⁷F₅). The luminescence intensity of Eu³⁺ increased with dopant concentration, whereas Pr³⁺ and Tb³⁺ exhibited optimal emission at 1 mol% and 0.5 mol%, respectively, followed by concentration quenching at higher doping levels.