Preparation and Luminescence Properties of Orange-red Phosphors Ca₃Y₂ (Si₃O₉)₂:Eu³⁺

A series of orange-red phosphors Ca₃Y_2-2x(Si₃O₉)₂:2xEu³⁺ were synthesized by a conventional solid-state reaction. Their photoluminescence properties were investigated by X-ray diffraction. The results show that the prepared Ca₃Y₂(Si₃O₉)₂:Eu³⁺ crystals are Ca₃Y₂ (Si₃O₉)₂ phase. There are two excitation bands, namely, the O^2-−Eu³⁺ intensive charge transition band (CTB) and the weak f − f transition absorption of Eu³⁺ in the excitation spectra. The main emissions are located at 587 and 610 nm under the excitation of 225 nm, respectively, corresponding to ⁵D₀→⁷F₁ and ⁵D₀→⁷F₂ transition, and the intensity of the former is similar to that of the latter. However, the intensive emission is located at 615 nm and the weak emission is located at 591 nm under the excitation of 392 nm. The decay time of ⁵D₀ level in Eu³⁺ was determined via the time resolved spectra. The effect of Eu³⁺ content on the emission spectra intensity of Ca₃Y₂(Si₃O₉)₂:Eu³⁺ was investigated. The luminescent intensity increases with increasing Eu³⁺ content. The concentration quenching does not occur.