First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide
First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide
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DOI：
10.1103/physrevb.73.115207
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发表时间：
2006-03-01
影响因子：
3.7
通讯作者：
Albe, K
中科院分区：
文献类型：
--
作者：
Erhart, P;Albe, K
为了研究氧在氧化锌中的自扩散，我们用密度泛函理论结合爬像微动弹性带方法进行了计算。为此，我们导出了纤锌矿晶体中空位和间隙的完整迁移路径，并推导出了与实验上可获得的示踪扩散系数相联系的表达式。计算的迁移势垒与辐照样品的退火实验结果一致。我们发现，在富锌和富氧条件下，空位和间隙机制分别占主导地位。这驳斥了空位机制可以在富氧大气中的实验中运行的观点。我们的结果为扩散实验的(重新)解释提供了基础，并为发展可靠的器件模拟连续介质模型铺平了道路。
We have performed density-functional theory calculations in conjunction with the climbing image nudged elastic band method in order to study the self-diffusion of oxygen in zinc oxide. To this end, we have derived the complete set of migration paths for vacancies as well as interstitials in wurtzite crystals and deduced expressions which provide the link to experimentally accessible tracer diffusion coefficients. The calculated migration barriers are consistent with annealing experiments on irradiated samples. We find that vacancy and interstitialcy mechanisms dominate under zinc and oxygen-rich conditions, respectively. This refutes the belief that vacancy mechanisms can be operational in experiments in oxygen-rich atmosphere. Our results provide the basis for the (re-)interpretation of diffusion experiments, and pave the way towards the development of reliable continuum models for device simulation.