Band structure of indium oxide: Indirect versus direct band gap
Band structure of indium oxide: Indirect versus direct band gap
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DOI：
10.1103/physrevb.75.153205
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发表时间：
2007-04-01
影响因子：
3.7
通讯作者：
Albe, Karsten
中科院分区：
文献类型：
--
作者：
Erhart, Paul;Klein, Andreas;Albe, Karsten
氧化铟带隙的性质仍然是一个有争议的问题。基于光学测量的间接带隙的存在已被建议，这是0.9至1.1 eV小于直接带隙在伽马点。这可能是由于O 2p和In 4d轨道在Gamma外的强烈混合造成的。我们已经进行了广泛的密度泛函理论计算，使用LDA+U和GGA+U方法来阐明的贡献，在4d态和自旋轨道耦合的价带结构上的效果。虽然间接的带隙获得，总的价带最大值和最高占据的水平在伽马点之间的能量差是小于50毫电子伏。它的结论是，实验观察不能与电子结构的缺陷自由体材料。
The nature of the band gap of indium oxide is still a matter of debate. Based on optical measurements the presence of an indirect band gap has been suggested, which is 0.9 to 1.1 eV smaller than the direct band gap at the Gamma point. This could be caused by strong mixing of O 2p and In 4d orbitals off Gamma. We have performed extensive density functional theory calculations using the LDA+U and the GGA+U methods to elucidate the contribution of the In 4d states and the effect of spin-orbit coupling on the valence band structure. Although an indirect band gap is obtained, the energy difference between the overall valence band maximum and the highest occupied level at the Gamma point is less than 50 meV. It is concluded that the experimental observation cannot be related to the electronic structure of the defect free bulk material.