White long-lasting phosphorescence generation in a CaAl₂Si₂O₈ : Eu²⁺, Mn²⁺, Dy³⁺ system through persistent energy transfer

Abstract

Abstract Based on the persistent energy transfer principle, Mn 2+ was introduced into a CaAl 2 Si 2 O 8 : Eu 2+ /Dy 3+ phosphor to achieve white long-lasting emissions. Eu 2+ , Mn 2+ and Dy 3+ tri-doped CaAl 2 Si 2 O 8 phosphors with various Mn 2+ concentrations were prepared via a solid-state reaction, and the crystal structure of the phosphors was identified by the x-ray diffraction technique. The luminescent properties of the Eu 2+ , Mn 2+ and Dy 3+ tri-doped CaAl 2 Si 2 O 8 phosphors were studied. The energy transfer behaviour from Eu 2+ to Mn 2+ was analysed within the framework of Dexter theory. The physical mechanism of energy transfer was assigned to the electric dipole–quadrupole interaction. It was also demonstrated that the colour coordinates of the phosphors can be tuned from the blue region to the white region in the colour space. Furthermore, the afterglow decay and thermoluminescence curves were measured, indicating excellent phosphorescence properties of the current phosphors.