第一性原理研究Fe掺杂SnO2材料的光电性质

采用基于第一性原理的线性缀加平面波(FP-LAPW)方法,研究Fe掺杂SnO₂材料电子结构和光学性质,包括电子态密度、能带结构、介电函数和其他一些光学图谱. 研究结果表明,掺Fe后材料均属于直接跃迁半导体,且呈现半金属性;随掺杂浓度增加,费米能级进入价带,带隙逐渐减小,Fe原子之间耦合作用增强;通过掺杂能够在一定程度上改变成键性质,使其具有金属键性质. 光学谱线(吸收谱、消光系数等)与介电函数虚部谱线相对应,均发生蓝移,各峰值与电子跃迁吸收有关,从理论上指出光学性质和电子结构的内在联系. 关键词： 能带结构 态密度 光学性质 介电函数

First-principles calculation on electronic structure and optical properties of iron-doped SnO2

By the full-potential linearized augmented plane wave method (FP-LAPW), we investigate the electronic structures and optical properties of Fe-doped SnO₂ system, including the density of states (DOS), band structure, dielectric function and other optical spectra. The calculation indicates that the Fe doped materials are all direct transition semiconductors with half-metallic property. With the increase of Fe-doping concentration, the Fermi level goes into valence band gradually, and the band gap reduces with the coupling of Fe atoms increasing. Moreover, impurity can change the property of the bond formation to some extent, and make it have metallic bond characteristic. Furthermore, we find that the optical spectrum (such as absorption spectrum), extinction coefficient, etc are blue shifted, corresponding to the imaginary part of dielectric function. The peaks are related to the transition of electrons, which indicates internal relationship between the electronic structures and optical properties theoretically.