A Single-Component White-Emitting CaSr₂Al₂O₆:Ce³⁺, Li⁺, Mn²⁺ Phosphor via Energy Transfer

A series of single-component Ce³⁺, Li⁺, Mn²⁺ ions codoped color-tunable CaSr₂­Al₂O₆ phosphors were synthesized by a high-temperature solid-state reaction, and the photoluminescence properties as well as the energy transfer mechanism from Ce³⁺ to Mn²⁺ ions have been investigated in detail. The Ce³⁺ activated phosphors have strong absorption in the range of 250–420 nm and can give a blue emission centered at about 460 nm. When Mn²⁺ ions are codoped, the emission of CaSr₂­Al₂O₆:​Ce³⁺, Li⁺, Mn²⁺ phosphors can be tuned from blue to red through adjusting the doping concentration of the Mn²⁺ ions, under the irradiation of 358 nm. When the concentration of Mn²⁺ is increased to 0.02, a warm-white light can be obtained with good CIE coordinates of (0.388, 0.323) and a low CCT of 3284 K. The energy transfer mechanism from the Ce³⁺ to Mn²⁺ ions is demonstrated to be a quadrupole–quadrupole interaction based on the analysis of the decay curves of the phosphors. The thermal quenching stability was also investigated. The results indicate that CaSr₂­Al₂O₆:​Ce³⁺, Li⁺, Mn²⁺ samples might have potential applications in <i>w</i>-LEDs