Investigation of the luminescent properties of Ce3+ doped and Ce3+/Mn2+ co-doped CaAl2Si2O8 phosphors

Abstract

A series of Ce³⁺ doped and Ce³⁺/Mn²⁺ co-doped CaAl₂Si₂O₈ phosphors have been synthesized in a reducing atmosphere (Ar/H₂) via a solid-state route and their photoluminescent properties have been investigated at room temperature. For the CaAl₂Si₂O₈:Ce³⁺ phosphor, a broad emission band at 430 nm is observed in addition to characteristic bands of Ce³⁺ peaking at 334 nm and 356 nm. The extra band is assigned to the presence of cationic vacancies naturally created to counterbalance the substitution of Ce³⁺ ions for Ca²⁺ alkaline-earth species. Its intensity can be significantly reduced when Ca²⁺ cations are replaced by the reaction i.e. when the amount of alkaline earth vacancies induced by the presence of Ce³⁺ cations is minimized. Moreover, the co-doping Ce³⁺/Mn²⁺ goes along with the appearance of energy transfers that make possible fine tuning of the CIE(x, y) parameters from blue to warm white and even yellow.