中文摘要：

使用基于密度泛函理论的CASTEP软件计算了BAM：Eu^2＋（BaMgAl10O17：Eu^2＋）荧光粉在SiN掺杂前后的能带、态密度、吸收光谱和Mulliken布居．Eu^2＋处于BR位置光吸收更强；SiN掺杂使处于BR位置的Eu^2＋的数量上升，而处于mO位置的Eu^2＋的数量下降，抵消了SiN掺杂降低Eu的态密度对光谱的影响,所以适量掺杂的SiN提高了BAM：Eu^2＋荧光粉的吸收发射光谱强度,Si—N键和Eu—N键的Mulliken布居数分别高于Al—O键和Eu-O键，说明Si—N键和Eu—N键的共价性分别强于Al^-键和Eu—O键,发光中心Eu^2＋局域结构共价性的增强降低了BAM：Eu^2＋镜面层的活性，这是SiN掺杂提高BAM：Eu^2＋荧光粉光学稳定性的主要原因。

英文摘要：

Using density functional theory, we studied band structure, density of states, optical proper- ties and Mulliken population of the pure and SiN doped BaMgAl10017：Eu^2＋ （BAM：Eu^2＋） phosphors. Calculation results showed that the bands of BAM：Eu2＋ were of low band energy dispersion, indicating large joint density of states, hence high performance of optical absorption and luminescence. BAM：Eu^2＋ showed stronger absorption intensity while Eu^2＋ occupied the BR sites instead of the mO sites. The concentration of Eu^2＋ at BR sites increased while that at mO sites decreased after Si-N doping. The influence of the variation of Eu^2＋ distribution on the spectra was stronger than the influence of the decrease of Eu^2＋ PDOS when SiN concentration was lower than 0.25, therefore the absorption and luminescence intensity of BAM：Eu^2＋ were enhanced. Mulliken population of Si-N bond was higher than A1-O bond, while that of Eu-N bond was higher than Eu-O bond as well, indicating that Si-N bonds and Eu-N bonds possessed higher covalence than Al-O bonds and Eu-N bonds respectively. The existence of Si-N bonds and Eu-N bonds enhanced the local covalence of Eu^2＋, hence the optical stability of BAM：Eu^2＋.