Synthesis and luminescence properties of RMgPO4:Mn2+ (R = Li, Na, and K) red phosphor

RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors are synthesized by a solid-state reaction method in air. The crystal structures and luminescence properties are investigated. A broad emission band peaking at 638 nm of RMgPO 4 :Mn 2+ (R = Li and Na) phosphors with excitation 408 nm is observed in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. KMgPO 4 :Mn 2+ phosphor with excitation 416 nm shows a broad emission band peaking at 658 nm in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. The optimal Mn 2+ ion concentration in RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors is about 5 mol%. The lifetimes of RMg 0.95 PO 4 :0.05Mn 2+ (R = Li, Na, and K) phosphors is ~6.21, 6.03, and 6.28 ms, respectively. The luminous mechanism is explained by Tanabe-Sugano diagram of Mn 2+ ion.