First-principles study on electronic structure of Sr2Bi2O5 crystal
First-principles study on electronic structure of Sr2Bi2O5 crystal
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DOI：
10.1016/j.jpcs.2011.08.030
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发表时间：
2011-12
影响因子：
4
通讯作者：
Y. Obukuro;Hiroyuki Nakamura;K. Obata;S. Matsushima;M. Arai;Kenkichiro Kobayashi
中科院分区：
文献类型：
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作者：
Y. Obukuro;Hiroyuki Nakamura;K. Obata;S. Matsushima;M. Arai;Kenkichiro Kobayashi
采用GGA方法计算了Sr 2Bi 2 O 5的电子结构。价带顶和导带底都位于Γ点。这意味着Sr 2Bi 2 O 5是直接带隙材料。价带最大值和导带最小值附近的宽能带色散预示着由带隙激发产生的空穴和电子具有高迁移率。导带由Bi 6p、Sr 4d和O 2 p能级组成。另一方面，价带可以分为两个能量区域，范围从-9.5到-7.9eV（下价带）和从-4.13到0 eV（上价带）。前者主要由Bi 6s态与O2 s和O2 p态的杂化构成，后者主要由O2 p态与Bi 6s和Bi 6p态的强相互作用构成。
The electronic structure of Sr2Bi2O5is calculated by the GGA approach. Both of the valence band maximum and the conduction band minimum are located at Γ-point. This means that Sr2Bi2O5is a direct band-gap material. The wide energy-band dispersions near the valence band maximum and the conduction band minimum predict that holes and electrons generated by band gap excitation have a high mobility. The conduction band is composed of Bi 6p, Sr 4d and O 2p energy states. On the other hand, the valence band can be divided into two energy regions ranging from −9.5 to −7.9eV (lower valence band) and from −4.13 to 0eV (upper valence band). The former mainly consists of Bi 6s states hybridizing with O 2s and O 2p states, and the latter is mainly constructed from O 2p states strongly interacting with Bi 6s and Bi 6p states.