Systematic study of ferroelectric, interfacial, oxidative, and doping effects on conductance of Pt/BaTiO3/Pt ferroelectic tunnel junctions
Systematic study of ferroelectric, interfacial, oxidative, and doping effects on conductance of Pt/BaTiO3/Pt ferroelectic tunnel junctions
复制标题
DOI：
10.1103/physrevb.85.064105
复制
发表时间：
2012-02
影响因子：
3.7
通讯作者：
Lei Shen;Tiejun Zhou;Zhaoqiang Bai;M. Zeng;J. Goh;Zhi-Min Yuan;G. Han;Bo Liu;Y. Feng
中科院分区：
文献类型：
--
作者：
Lei Shen;Tiejun Zhou;Zhaoqiang Bai;M. Zeng;J. Goh;Zhi-Min Yuan;G. Han;Bo Liu;Y. Feng
采用非平衡绿色函数方法结合密度泛函理论，系统地研究了BaTiO基铁电隧道结（Pt/BaTiO/Pt）的铁电、界面、氧化和掺杂效应对电子输运的影响.与非铁电BaTiO相比，铁电效应降低了隧道电导，这是由于5（和）带的大衰减速率。由于电子主要通过Ti-Obonding态传输，因此TiO终止的界面比BaO终止的界面显示出更好的隧穿电导。界面氧化强烈降低电导由于捕获的电子和界面电荷本地化的额外的O离子，而Nb掺杂增强的电导由于离域分布的电荷的轨道上的传输通道。我们的研究为铁电势垒隧道结的实际应用提供了有益的指导。
Using the nonequilibrium Green's function method combined with density functional theory, we systematically study the ferroelectric, interfacial, oxidative, and doping effects on electron transport of BaTiO-based ferroelectric tunnel junctions (Pt/BaTiO/Pt). The ferroelectric effect reduces the tunneling conductance compared to nonferroelectric BaTiOdue to the large decay rate of the5 (and) band. The TiO-terminated interface shows a better tunneling conductance than the BaO-terminated interface since electrons mainly transport through the Ti-Obonding state. Interfacial oxidation strongly reduces the conductance due to trapping of electrons and interfacial charge localization by additional O ions, while Nb doping enhances the conductance due to the delocalized distribution of charges on orbitals of the transport channel. Our studies provide a useful guide to practical applications of tunnel junctions with ferroelectric barriers.