First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects
First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects
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DOI：
10.1103/physrevb.73.205203
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发表时间：
2006-05-01
影响因子：
3.7
通讯作者：
Klein, Andreas
中科院分区：
文献类型：
--
作者：
Erhart, Paul;Albe, Karsten;Klein, Andreas
为了弥补有限尺寸效应和能带结构的不正确描述的影响，对氧化锌中的本征点缺陷特性进行了密度泛函理论（DFT）计算。应用具有经验自相互作用校正 (GGA+U) 的广义梯度近似 (GGA) 来校正 GGA-DFT 计算中固有的共价性的高估。通过应用广泛的有限尺寸缩放和补偿电荷校正来解释弹性和静电图像相互作用。推导了尺寸校正的形成焓和体积以及它们的电荷态依赖性。我们的结果部分证实了早期的计算，但揭示了更多的跃迁能级：（1）对于锌间隙和氧空位，跃迁能级都接近导带最小值。 (2) 锌空位显示出一个相当接近价带最大值的转变，而另一个转变则接近计算的带隙中间。 (3) 对于氧间隙原子，跃迁能级发生在价带最大值和导带最小值附近。
Density-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite-size effects and the improper description of the band structure. The generalized gradient approximation (GGA) with empirical self-interaction corrections (GGA+U) was applied to correct for the overestimation of covalency intrinsic to GGA-DFT calculations. Elastic as well as electrostatic image interactions were accounted for by application of extensive finite-size scaling and compensating charge corrections. Size-corrected formation enthalpies and volumes as well as their charge state dependence have been deduced. Our results partly confirm earlier calculations but reveal a larger number of transition levels: (1) For both the zinc interstitial as well as the oxygen vacancy, transition levels are close to the conduction band minimum. (2) The zinc vacancy shows a transition rather close to the valence band maximum and another one near the middle of the calculated band gap. (3) For the oxygen interstitials, transition levels occur both near the valence band maximum and the conduction band minimum.