Synthesis and luminescence properties of double perovskite Ba 2 MgGe 2 O 7 :Mn 4+ deep red phosphor

Abstract A deep red-emitting Ba 2 MgGe 2 O 7 :Mn 4+ (BMG:Mn 4+ ) phosphor was synthesized by conventional solid-state reaction. 4 A 2g → 4 T 1g , 4 A 1g → 4 T 2g , and 4 A 2g → 2 T 2g transitions of Mn 4+ ions resulted in three absorption bands centered at 305, 330, and 420 nm, respectively. The phosphor showed a broad emission band from 600 nm to 700 nm due to 2 E→ 4 A 2 transition of Mn 4+ ions. The highest luminous peak located at 660 nm, and the highest luminous intensity was achieved at high Mn 4+ concentration (0.013). Multipolar interaction was the major mechanism for fluorescence quenching, and dipole–dipole interaction was the type of interaction mechanism between Mn 4+ ions. Fluorescence lifetimes decreased from 0.898 ms to 0.746 ms, which accorded with the requirement of white light-emitting diode phosphor. Color coordinates of BMG:Mn 4+ phosphors (0.721, 0.279) were close to the standard values of the National TV Standards Committee.