Rare-earth free broadband Ca3Mg3P4O16:Mn2+ red phosphor: Synthesis and luminescence properties

Rare-earth-free red-emitting Ca3Mg3P4O16:Mn2+ (CMPO:Mn2+) phosphor is synthesized by high temperature solid-state reaction method in air. The crystal structures and luminescence properties are investigated. Broad emission band peaking at similar to 625 nm of CMPO:Mn2+ phosphor with excitation 410 nm is observed in the range of 510 - 790 nm due to the T-4(1)(G) -> (6)A(1) transition of the Mn2+ ion. The full width at half-maximum is similar to 120 nm. Excitation bands are assigned to the [(6)A(1) -> E-4(D-4), T-4(2)(D), [(4)A(1)(G), E-4((4)G), and T-4(1)(G)] transitions, respectively. The optimal Mn2+ ion concentration in CMPO:Mn2+ phosphor is similar to 5 mol%. The lifetime of CMPO:0.05Mn(2+) phosphor is similar to 5.75 ms. The luminous mechanism of Mn2+ ion in CMPO:Mn2+ phosphor is explained by Tanabe-Sugano diagram and the simple energy level diagram of Mn2+ ion. The paper content is helpful for the research of novel Mn2+-doped materials.