Synthesis and photoluminescence properties of LaAlO3:Mn4+, Na+ deep red-emitting phosphor

LaAlO 3 :Mn 4+ and LaAlO 3 :Mn 4+ , Na + deep red-emitting phosphors are synthesized by a solid-state reaction method in air. Their crystal structures, lifetimes, and luminescence properties are investigated, respectively. PLE spectrum monitored at 730 nm contains three PLE bands peaking at ~276, 325, and 500 nm within the range 200–550 nm, and PL spectrum with excitation 325 nm exhibits two PL band peaks located at ~703 and 730 nm owing to anti-stokes vibronic sidebands associated with the excited state 2 E of Mn 4+ ion and the 2 E  →   4 A 2 transition of Mn 4+ ion, respectively. The optimal Mn 4+ doping concentration is ~0.8 mol%. Lifetime of LaAl 0.992 O 3 :0.8 %Mn 4+ phosphor is ~0.92 ms. Na + ion as charge compensator can improve obviously the luminescence properties of LaAlO 3 :Mn 4+ phosphor due to the charge compensation. The luminous mechanism of Mn 4+ ion is explained by using Tanabe–Sugano diagram of Mn 4+ ion in octahedral crystal field. The contents of this paper will be helpful to develop novel Mn 4+ -doped materials and improve their luminescence properties.