A narrow-band green-emitting LaMgAl11O19:Ce3+, Mn2+ phosphor: Structure, energy transfer and luminescence

Abstract

A narrow-band green-emitting LaMgAl₁₁O₁₉: Mn²⁺, Ce³⁺ phosphor was synthesized through high-temperature solid-state reaction. The phase, luminescent properties, and energy transfer mechanism from Ce³⁺ to Mn²⁺ in LaMgAl₁₁O₁₉ were systematically investigated. The results reveal that Ce³⁺ ions serve as effective sensitizers for Mn²⁺ in LaMgAl₁₁O₁₉, leading to enhanced green emission at 525 nm, upon 320 nm excitation. The energy transfer from Ce³⁺ to Mn²⁺ is found to occur via dipole-dipole interactions, with a calculated critical transfer distance of 14.24 Å. The quantum efficiency of the optimized sample reaches 74.3 %, and the phosphor exhibits excellent thermal stability, retaining 92 % of its luminescence intensity at 150 °C. These results indicate the LaMgAl₁₁O₁₉: Mn²⁺, Ce³⁺phosphors exhibit high potential for wide color gamut white light-emitting diode (wLED) backlighting applications.