A novel red emitting phosphor CaIn2O4:Eu3+, Sm3+ with a broadened near-ultraviolet absorption band for solid-state lighting

Red phosphor of CaIn2O4:Eu3+, Sm3+ is synthesized by solid state reaction. The 5D0 → 7F2 transition of Eu3+ is dominantly observed in the photoluminescence spectrum, leading to a red emission of the phosphor. The doped Sm3+ is found to be efficient to sensitize the emission of Eu3+ and be effective to extend and strengthen the absorption of near-UV light with wavelength of 400–405 nm, and the energy transfer from Sm3+ to Eu3+ occurs and is discussed. The effect of the molar concentration of Sm3+ on the emission intensities of the phosphor CaIn2O4:Eu3+, Sm3+ is investigated. The temperature quenching effect is also measured from room temperature to 425 K, and the emission intensity of the phosphor at 425 K shows about 85% of that at room temperature. Furthermore, the chromaticity coordinates, the emission intensities and the conversion efficiencies of CaIn2O4:Eu3+, Sm3+ are compared to those of the conventional red phosphor of Y2O2S:Eu3+.