Luminescent Properties of Mn²⁺ in Hexagonal Aluminates under Ultraviolet and Vacuum Ultraviolet Excitation

Abstract

Mn2+-doped xBaO·6Al2O3 and BaMgAl10O17 phosphors were prepared by solid-state reaction. The investigation of vacuum ultraviolet (VUV) excitation spectra of these phosphors exhibits that 0.82BaO·6Al2O3:Mn2+ and BaMgAl10O17:Mn2+ have a stronger absorption than BaO·6Al2O3:Mn2+ at about 147 nm. The emission spectra under VUV excitation demonstrated that 0.82BaOBa·6Al2O3:Mn2+ and BaMgAl10O17:Mn2+ have a higher luminescent intensity than BaO·6Al2O3:Mn2+. The lifetime analysis indicates that they have similar decay times, indicating that 0.82BaOBa·6Al2O3:Mn2+ and BaMgAl10O17:Mn2+ can be used as luminescent materials for plasma display panels. We observed that the critical concentration of the Mn2+ ions by host excitation is different from that of Mn2+ direct excitation, revealing a different mechanism of energy transfer. The critical distance was calculated. A model was suggested to explain the process of the energy transfer from the host to the Mn2+ ions.