Preparation and photoluminescence characteristics of Li2Mg3SnO6:Mn4+ deep red phosphor

Li 2 Mg 3 SnO 6 :Mn 4+ deep red phosphor is synthesized by high-temperature solid-state reaction method in air. With excitation 330 and 480   nm, the emission band peaking at ∼670   nm within the range 600–790   nm is observed owing to the 2 E   →   4 A 2 transition of Mn 4+ ion. Excitation bands peaking at ∼330, 395, and 480   nm in the range of 220–600   nm indicate that Li 2 Mg 3 SnO 6 :Mn 4+ phosphor can be effectively excited by (near) ultraviolet and blue light-emitting diode chips. The optimal Mn 4+ ion concentration is ∼0.4 mol%. Fluorescence lifetime and quantum efficiency of Li 2 Mg 3 SnO 6 :0.4%Mn 4+ phosphor with excitation 330   nm are ∼266.67   μs and 36.3%, respectively. The luminous mechanism is explained by the Tanabe-Sugano energy level diagram of Mn 4+ in the octahedron.