采用第一性原理研究钼掺杂浓度对ZnO物性的影响

发布时间：2018-07-31 08:36

【摘要】：Mo掺杂ZnO的吸收光谱红移和蓝移两种相互冲突的实验结果均有报道,但是仍然没有合理解释.为了解决该问题,本文采用基于密度泛函理论的广义梯度近似平面波超软赝势+U方法,用第一性原理分析了Zn_(0.9583)Mo_(0.0417)O,Zn_(0.9375_Mo_(0.0625_O,Zn_(14)Mo_2O的能带结构、态密度和吸收光谱分布.结果表明,Mo掺杂量为2.08 at%—3.13 at%的范围内,随着掺杂量的增加,体系的体积逐渐增大,形成能逐渐升高,稳定性逐渐下降,掺杂逐渐困难.与此同时,所有掺杂体系均转化为n型简并半导体.与未掺杂ZnO相比,掺杂体系的带隙均变窄,吸收光谱均发生红移,Mo掺杂量越增加,掺杂体系带隙变窄减弱、吸收光谱红移减弱、电子有效质量越减小、电子浓度越减小、电子迁移率越减小、电子电导率越减小.同时,磁矩减小,掺杂体系的居里温度能达到室温以上.
[Abstract]:The experimental results of red shift and blue shift of Mo doped ZnO have been reported, but there is still no reasonable explanation. In order to solve this problem, the generalized gradient approximation plane-wave ultra-soft pseudopotential U method based on density functional theory is used to analyze the energy band structure, density of states and absorption spectrum distribution of Zn _ (0.9583) Mo _ (0.0417) O _ (0. 9375) O _ (0.0417) O _ (0. 9375) O _ (2) S _ (14) Mo_2O. The results show that in the range of 2.08 at%-3.13 at%, the volume and formation energy of the system increase gradually, the stability decreases and the doping becomes more difficult with the increase of the doping amount. At the same time, all doping systems are converted into n-type degenerate semiconductors. Compared with the undoped ZnO, the band gap of the doped system becomes narrower, the absorption spectrum increases, the band gap of the doped system decreases, the red shift of the absorption spectrum weakens, the effective mass of the electron decreases and the electron concentration decreases. The lower the electron mobility, the smaller the electronic conductivity. At the same time, the magnetic moment decreases and the Curie temperature of the doped system reaches above room temperature.
【作者单位】：内蒙古工业大学理学院;内蒙古自治区薄膜与涂层重点实验室;上海海事大学文理学院;
【基金】：国家自然科学基金(批准号:61366008,61664007,11672175)资助的课题~~
【分类号】：TN304.21

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