Preparation and fluorescence property of red-emitting Eu-activated amorphous calcium silicate phosphor

This paper describes the energy efficient synthesis of a red-emitting Eu³⁺-activated amorphous calcium silicate phosphor produced by heating a Eu³⁺-activated calcium silicate hydrate phosphor. Concentration quenching of the Eu³⁺-activated calcium silicate hydrate phosphor was not observed and the emission intensity did not decrease up to a Eu/(Ca+Eu) atomic ratio of 0.46. Heating of the Eu³⁺-activated calcium silicate hydrate (Eu/(Ca+Eu) atomic ratio = 0.32) phosphor produced an amorphous Eu³⁺-activated calcium silicate phosphor, which had a maximum emission intensity at 870 °C and emitted in the red under near-ultraviolet irradiation (395 nm). The emission intensity of the Eu³⁺-activated amorphous calcium silicate phosphor was about half that of a commercial BaMgAl₁₀O₁₇:Eu²⁺ phosphor, and shows great potential for application in white light-emitting diodes.