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

We report a newly found strong disturbing effect orAl addition to the intensity ratios of blue and green emissions from single host full-colour phosphor of Ba3MgSi2-xAlxO8：0.02Eu^2＋, 0.1Mn^2＋ for near-UV excited white light. The phase-pure silicate phosphor in the size of around 4μm 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 orAl 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 oral content. The Raman spectroscopy verifies the modifying effect oral ion to the tetrahedral network in silicate hosts. We assume that by addition of Al ion, the amount of those two kinds of Eu^2＋ substituting for those two kinds of Ba^2＋ 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.     

硅酸盐单基质白光LED荧光体的制备和光谱性质

用喷雾热解溶胶凝胶方法制备了平均粒径为4.45μm大小的同一基质Ba₃MgSi₂O₈:Eu²⁺,Mn²⁺三色发射合成白光的LED荧光体,研究了掺杂铝离子对荧光体的微结构和发射光谱的影响。实验发现,在375nm的激发下,红绿蓝(RGB)三种颜色峰的位置分别是608,500,437nm。微量Al离子的掺入会使荧光粉蓝光和绿光的相对强度发生明显变化,而红光的强度基本不变。因此,荧光体的色坐标位置可以通过掺入不同数量的铝离子来调控。从微结构机制上讨论了铝离子对基质离子的配位、格位和能量状况、发射光谱影响的内在规律。该稀土硅酸盐基质表现出的RGB三色发射特征,可成为重要的新型白光荧光体材料。