Structure and electrical levels of point defects in monoclinic zirconia
Structure and electrical levels of point defects in monoclinic zirconia
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DOI：
10.1103/physrevb.64.224108
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发表时间：
2001-12-01
影响因子：
3.7
通讯作者：
Nieminen, RM
中科院分区：
文献类型：
--
作者：
Foster, AS;Sulimov, VB;Nieminen, RM
我们用平面波密度泛函理论(DFT)计算了单斜氧化锆中氧空位和间隙氧原子的形成能、弛豫结构和电子能级。研究了正、负电荷空位和间隙氧原子的原子结构。计算了不同电荷态的间隙氧原子和氧空位相对于氧化锆导带底部的电离能和电子亲和能。利用在硅衬底上生长的氧化锆薄膜界面的实验带偏移量，我们找到了缺陷能级相对于硅导带底部的位置。结果表明，间隙氧原子和带正电荷的氧空位可以捕获氧化锆导带底部和硅中的电子。中性氧空位是从硅价带注入的电子的浅空穴陷阱。计算预测了单斜氧化锆中O中心的负U和V+中心相对于歧化成V2+和V-0的稳定性。
We performed plane wave density functional theory (DFT) calculations of formation energies, relaxed structures, and electrical levels of oxygen vacancies and interstitial oxygen atoms in monoclinic zirconia. The atomic structures of positively and negatively charged vacancies and interstitial oxygen atoms are also investigated. The ionization energies and electron affinities of interstitial oxygen atoms and oxygen vacancies in different charge states are calculated with respect to the bottom of the zirconia conduction band. Using the experimental band offset values at the interface Of ZrO2 films grown on silicon, we have found the positions of defect levels with respect to the bottom of silicon conduction band. The results demonstrate that interstitial oxygen atoms and positively charged oxygen vacancies can trap electrons from the bottom of the zirconia conduction band and from silicon. Neutral oxygen vacancy serves as a shallow hole trap for electrons injected from the silicon valence band. The calculations predict negative U for the O- center and stability of V+ centers with respect to disproportionation into V2+ and V-0 in monoclinic zirconia.