Luminescence and Structural Properties of High Stable Si – N ‐Doped BaMgAl ₁₀ O ₁₇ : Eu ²⁺ Phosphors Synthesized by a Mechanochemical Activation Route

Abstract

Highly thermal stable Si – N ‐doped BAM ( BaMgAl 10 O 17 : Eu 2+ ) phosphors have been successfully synthesized by a mechanochemically assisted solid‐state reaction method. Mechanical milling greatly improved the amount of Si – N pairs substituted for Al – O pairs in BAM lattice>. Si – N incorporation improves the photoluminescence ( PL ) properties and the color purity, reduces the thermal quenching, and most importantly, increases the thermal stability of the BAM phosphors significantly. The interpretation of the positive influence of Si – N doping was attributed to the local structure of the produced phosphors, which was analyzed with the aid of first‐principles density functional calculations. This analysis showed that the substitution of Al – O pairs with Si – N pairs should preferentially occur in the boundary between the spinel layer and the conduction layer of the BAM phosphor, leading to a compression of the conduction layer. Eu 2+ ions prefer to substitute the N ‐coordinated Ba 2+ ions in the lattice of Si – N ‐doped BAM phosphors, leading to a strong Eu – N bonding. The results of these calculations agree fairly well with the results recorded experimentally, specifically the electron paramagnetic resonance ( EPR ) spectra, the X‐ray absorption fine structure ( XAFS ), thermoluminescence spectra ( TL ), and decay behaviors.