Enhancing the luminescence performance of an LED-pumped Mn⁴⁺-activated highly efficient double perovskite phosphor with A-site defectsvialocal lattice tuning

Abstract

Altering the local symmetry of activator by lattice tuning is considered an effective strategy to optimize the luminescence performance of phosphors. Herein, a novel Mn4+-activated double perovskite phosphor of La1.67MgTaO6...

Luminescence enhancement of Mn4+‐activated double‐perovskite phosphors for LEDs through a co‐replacement strategy

“…The lowest point of the conduction band and the highest point of the valence band of the LaAlO 3 matrix are located at point G, and the bottom of the conduction band and the top of the valence band of the MLTO matrix are located at point D, indicating that both phosphors are direct bandgap materials. The bandgap width of the MLTO sample is derived from the Tauc curve with the following equation 39 : $$$$\begin{equation}{(\alpha h\nu )}^n = K\left( {h\nu - {E}_g} \right)\end{equation}$$$$where α is the absorption coefficient, hν represents the photon energy, and K is a constant. n with a value of 2 or 1/2 indicates that the sample is a direct or indirect bandgap semiconductor.…”

“…Compared to fluorides, chalcogenide oxides have a large number of octahedral structures while their physicochemical properties are more stable, green, and moisture resistant. Many Mn 4+ ion‐doped oxides have been reported, such as Ba 2 La 2 ZnW 2 O 12 : Mn 4+ , 11 La 1.67 MgTaO 6 : Mn 4+ , 12 Sr 2 LuTaO 6 : Mn 4+ , 13 Ca 2 LuTaO 6 : Mn 4+ , 14 and SrLaLiTeO 6 : Mn 4+ 15 . Different matrices have a great influence on the internal quantum efficiency (IQE) and thermal stability of Mn 4+ ‐activated phosphors, so it is important to study the structure of matrix 6 .…”