Finite element simulations on piezoelectric modulation of ZnO grain boundary barrier height
Finite element simulations on piezoelectric modulation of ZnO grain boundary barrier height
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DOI：
10.1063/1.5109666
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发表时间：
2019-11
影响因子：
3.2
通讯作者：
Zi-Qi Zhou;K. A. Taylor;E. Gjonaj;T. Frömling;Bai-Xiang Xu
中科院分区：
文献类型：
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作者：
Zi-Qi Zhou;K. A. Taylor;E. Gjonaj;T. Frömling;Bai-Xiang Xu
ZnO中晶界势垒的建模是复杂的，因为势垒发育的物理机制及其受外界影响因素的修饰是复杂的。研究表明，机械诱导的压电电荷可以显著地调制势垒高度。这使得ZnO-ZnO界面适用于先进的压电系统，其中电导率由机械应力调节。然而，为了应用这种效应，定制界面的能力和压电冲击的准确物理描述是必要的。在这项工作中，开发了一个有限元（FE）模型来提供这样的描述。由于其完全的机械-静电耦合，该模型对自由空间电荷的预先假设很少，可以进行多维研究，并允许访问电荷，能量和电场分布等量。此外，有限元模型固有地包含了逆压电效应和各向异性效应，这些效应对势垒高度有很大的影响。此外，该模型可用于考虑界面性质复杂性的高级三维微观结构模拟。
Modeling grain boundary potential barriers in ZnO is complicated, because the physical mechanism for barrier development and its modification by external influence factors are complex. It has been shown that the barrier height can be significantly modulated by mechanically induced piezoelectric charge. This makes ZnO-ZnO interfaces suitable for advanced piezotronic systems, in which conductivity is modulated by mechanical stress. However, in order to apply this effect, the ability to tailor the interfaces and an accurate physical description of the piezoelectric impact are necessary. In this work, a finite element (FE) model was developed to provide such a description. Due to its full mechanical-electrostatic coupling, this model requires few prior assumptions about the free spatial charge, enables multidimensional study, and allows access to quantities such as charge, energy, and electric field distributions. Moreover, the FE model inherently includes inverse piezoelectric and anisotropy effects, which are shown to have a large impact on barrier height. Additionally, it is illustrated that this model can be used for advanced 3D microstructure simulations taking the complexity of the interface properties into account.