Synthesis and Luminescence Properties of Tb3+-Doped Aluminum Oxynitride

Abstract

We report an experimental study concerned with the synthesis and luminescence properties of Al₅O₆N aluminum oxynitride doped with Tb³⁺ in the concentration range 0.025–0.5 at %. All of the samples, prepared by firing appropriate mixtures in a nitrogen atmosphere at 1600°C, consisted predominantly of phase-pure γ-ALON (Al₅O₆N), with small amounts of impurity phases: Al₇O₃N₅ aluminum oxynitride and Tb₃Al₅O₁₂ terbium aluminate. Their pulsed cathodoluminescence and photoluminescence spectra contain emission bands typical of Tb³⁺ ions. The concentration threshold for luminescence quenching corresponds to a Tb³⁺ concentration at a level of 0.4 at %. A Tb³⁺ cross relaxation effect found in Al₅O₆N:Tb³⁺ is discussed and photoluminescence spectra are shown to be inhomogeneous at low Tb³⁺ concentrations in Al₅O₆N.