论文部分内容阅读
采用基于密度泛函理论的第一性原理赝势平面波方法,对稀土元素La掺杂β-FeSi2的几何结构、能带结构、态密度进行了理论计算.几何结构的计算表明:La掺杂后使β-FeSi2的晶格常数a、b、c都变大了,使得晶胞体积也相应增大;La掺杂β-FeSi2的置换位置为FeⅡ位.电子结构的计算表明:能带结构为直接带隙,禁带宽度变窄仅为0.013eV;费米面进入价带,能带数目增多,态密度峰值减小,费米面附近载流子浓度显著增大.这些结果为β-FeSi2光电材料掺杂改性的实验和理论研究提供理论依据.
The geometrical structure, energy band structure and density of states of La-doped β-FeSi2 are calculated by first-principles pseudopotential plane wave method based on density functional theory.The calculation of geometric structure shows that La-doped The lattice constants a, b, c of β-FeSi2 become larger, so that the unit cell volume also increases correspondingly; the substitution position of La-doped β-FeSi2 is Fe Ⅱ. The calculation of electronic structure shows that the band structure is Direct band gap, narrowing the band gap is only 0.013eV; Fermi surface into the valence band, the band number increased, the peak value of state density decreases, the carrier concentration near the Fermi surface significantly increased.These results for the β-FeSi2 photoelectric material Doping modified experimental and theoretical studies provide a theoretical basis.