Luminescence performance of laser synthesized Al₂O₃:Eu³⁺ nanophosphors depending on synthesis conditions

Al₂O₃:Eu³⁺ nanophosphors were prepared by laser vaporization method in a flowing mixture of Ar/He and O₂. Luminescence properties of Al₂O₃:Eu³⁺ nanophosphors are predominantly determined by Eu³⁺ ions red emission with inhomogeneously broadened bands in the region of 550-750 nm corresponding to ⁵D₀ →⁷F_J transitions of Eu³⁺ (J = 0 - 4). Hypersensitive electric dipole transition ⁵D₀ →⁷F₂ dominates in the spectrum and is responsible for the red emission. The effect of crystallite size on luminescence properties of Al₂O₃:Eu³⁺ nanocrystals was observed. It was shown that the introduction of oxygen during the synthesis improves the luminescence performance. The obtained chromaticity coordinates and high absolute QY (~ 14%) indicate the possibility of using red nanophosphors based on Al₂O₃:Eu³⁺