Unusual Nonlinear Strain Dependence of Valence-Band Splitting in ZnO
Unusual Nonlinear Strain Dependence of Valence-Band Splitting in ZnO
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DOI：
10.1103/physrevb.86.155205
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发表时间：
2012-10
影响因子：
3.7
通讯作者：
Yelong Wu;Guangde Chen;S. Wei;M. Al‐Jassim;Yanfa Yan
中科院分区：
文献类型：
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作者：
Yelong Wu;Guangde Chen;S. Wei;M. Al‐Jassim;Yanfa Yan
利用第一性原理的能带结构计算，研究了ZnO价带边缘的晶体场分裂和自旋轨道分裂，以及它们与应变的关系。与其他传统半导体不同的是，ZnO的价带分裂随应变的变化表现出强烈的非线性依赖性，晶体场分裂的斜率作为应变的函数甚至可以改变符号。我们的分析表明，ZnO中这种不寻常的行为是由于Zn的3d态和氧的2p态之间的强耦合。本文给出了ZnO在不同应变水平下的价带有序映射图，这对设计基于ZnO的光电器件具有重要意义
Using first-principles band structure calculations, we investigate the crystal-field splitting and spin-orbit splitting at the valance band edge of ZnO, and their dependence on the strain. Di ff erent from other conventional semiconductors, the variation of the valance-band splitting of ZnO shows a strong nonlinear dependence on the strain and the slope of the crystal-field splitting as a function of strain can even change sign. Our analysis shows that this unusual behavior in ZnO is due to the strong coupling between Zn 3 d states and oxygen 2 p states. A mapping of the valence-band ordering in ZnO under di ff erent strain levels is provided which will be useful in designing ZnO based optoelectronic devices