Intense blue-emitting Ca₅Al₈O₁₄: Eu phosphor for mercury free lamp

摘要

The calcium aluminates doped with Eu ions, Ca₅Al₈O₁₄: Eu, phosphors are prepared by the combustion method. The formation of crystalline aluminates was confirmed by X-ray diffraction pattern. The prepared phosphors were characterized by SEM, TGA, DTA, particle size analyzer and Photoluminescence (PL) techniques. From the UV-excited luminescence spectra it was found that the Eu ions acts as a luminescent centre with luminescence at the blue (λ _max = 470 nm) region due to 4f 65d 1 → 4f 7 transition. The excitation spectra show the broad band at 355 nm wavelength (λ _em = 470 nm). The excitation 355 nm is a mercury free excitation and therefore Ca₅Al₈O₁₄: Eu may be useful for the solid state lighting phosphor in lamp industry. Keywords Ca₅Al₈O₁₄ - PL - phosphor - noncentrosymmetric PACS Nos. 61.66.Fn - 61.72.Ww - 61.50.Ah