M₈MgSc(PO₄)₇:xDy³⁺ (M = Ca/Sr) Single-Phase Full-Color Phosphor with High Thermal Emission Stability

Two series of phosphors of Ca₈MgSc(PO₄)₇:Dy³⁺ and Sr₈MgSc(PO₄)₇:Dy³⁺ single-phase white-emitting phosphors with high thermal emission stability are synthesized by the high-temperature solid-state reaction. The crystal structure, photoluminescence (PL), PL excitation (PLE), and thermal PL quenching spectra of Ca₈MgSc(PO₄)₇:xDy³⁺ and Sr₈MgSc(PO₄)₇:xDy³⁺ were investigated and compared in detail. Upon excitation at 387 nm, M₈MgSc(PO₄)₇:xDy³⁺ (M = Ca/Sr) showed white emission centered at 480, 571, 660, and 754 nm. The white-emitting Dy-phosphor Ca₈MgSc(PO₄)₇:Dy³⁺ (CMSP:Dy) had good terminal stability. The emission intensity of Ca₈MgSc(PO₄)₇:Dy³⁺ still remained 95.2% of that at room temperature at 160 °C, and remained 77.3% at 300 °C under 387 nm excitation.