Crystal structure and photoluminescence properties of blue-green-emitting Ca_1−xSr_xZr₄(PO₄)₆: Eu²⁺ (0≤x≤1) phosphors

Ca_1−xSr_xZr₄(PO₄)₆: Eu²⁺ (0≤x≤1) was synthesized by a conventional solid‐state reaction for the first time. XRD data and the Rietveld refinement analysis confirm that the samples are single phase and continuous solid solutions are formed in the full range of 0≤x≤1. The emission peak can be tuned from 492 to 463 nm accompanied by a band narrowing from 87 to 68 nm due to the combined effects of crystal field regulation and site-preference of Eu²⁺. Both luminescence decay times and thermal stabilities of the phosphors show a non-linear dependence on the Sr²⁺ content. The insensitivity of thermal quenching properties of Ca_1−xSr_xZr₄(PO₄)₆: Eu²⁺ to the Sr²⁺ content was explained by the underlying mechanism of thermal ionization of 5d electron into the host conduction band.