Room and high temperature photoluminescence of Eu²⁺ doped CaAl₂Si₂O₈ phosphors

Abstract

CaAl₂Si₂O₈:Eu²⁺ phosphor powder was prepared by a solid state reaction method. Its photoluminescence property at room and high temperature was investigated. Based on the photoluminescence analyses, the physical mechanisms for red-shift, concentration quenching and thermal quenching were revealed. This phosphor shows broad band absorption and emission corresponding to Eu²⁺ transition between the 4f⁷ ground state and 4f⁶5d¹ splitting states. The emission spectra show red-shift, which is brought by the increase of the crystal splitting of Eu²⁺ 5d electron in the lattice. Concentration quenching occurs when Eu²⁺ concentration is more than 5 mol%. The dipole–dipole interaction dominates the concentration quenching. When the temperature is increased to 150 °C, the photoluminescence intensity quenches to 67%. CaAl₂Si₂O₈:Eu²⁺ could be a candidate for use in pc-wLEDs. And this study may be favorable for understanding the Eu²⁺ photoluminescence process in the lattice.