Colour Tuning of Single Host Phosphors for White Light by Al Addition

摘要

@@ We report a newly found strong disturbing effect of Al addition to the intensity ratios of blue and green emissions from single host full-colour phosphor of Ba3MgSi2-xAlxO8:0.02Eu2+, 0.1Mn2+ for near-UV excited white light.The phase-pure silicate phosphor in the size of around 4 μm is prepared by salt-assisted spray pyrolysis route,having three-colour emissions at the wavelength peak values of 437nm, 500 nm and 608 nm simultaneously under the excitation of 375 nm. The amount variation of Al ion added to the phosphor host results in a drastic change of the intensity ratio between green and blue emissions, while the intensity of red light keeps unchanged. As a consequence, the combination of three colours lies in the white light region and can be tuned by precisely controlled addition of Al content. The Raman spectroscopy verifies the modifying effect of Al ion to the tetrahedral network in silicate hosts. We assume that by addition of Al ion, the amount of those two kinds of Eu2+ substituting for those two kinds of Ba2+ lattice sites with distinct energy levels of blue and green featured emissions can be adjusted to contribute to diversification of the ratios of blue and green emissions.