Structure and optical properties under VUV/UV excitation of EU2+ doped alkaline earth aluminate phosphors

Polycrystalline hexagonal alkaline earth aluminates M3Al16O27 doped by divalent europium were prepared by solid state reaction. The crystal structure and optical properties at room temperature were investigated. The structure parameters were refined using Rietveld refinement procedures. The space group of the materials is P6(3)/mmc. Eu2+ ions occupy the 2d cation position of the large cation in the unit cell. The blue emission of the phosphors due to transitions between 4F(6)5d and 4f(7) configurations of the Eu2+ ion can be excited by UV radiation and very efficient also by VUV radiation. Spectral position and band width at half height of the emission band as well as the shape of the excitation spectrum and the luminous flux of the investigated aluminate phosphors depend on their composition. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.