Direct Atom-by-Atom Chemical Identification of Nanostructures and Defects of Topological Insulators
Direct Atom-by-Atom Chemical Identification of Nanostructures and Defects of Topological Insulators
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拓扑绝缘体纳米结构和缺陷的直接原子对原子化学识别
DOI：
10.1021/nl401186d
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发表时间：
2013-06-01
期刊：
影响因子：
10.8
通讯作者：
Zhang, Ze
中科院分区：
文献类型：
--
作者：
Jiang, Ying;Wang, Yong;Zhang, Ze
我们提出了一个直接的原子的原子化学鉴定的拓扑绝缘体（TI）的纳米结构和缺陷的国家的最先进的原子映射技术。结合这种技术和密度泛函理论计算，我们确定和解释的Bi 2 Te 3-xSex三元TI的层化学演化。我们还揭示了一个长期被忽视的，但至关重要的扩展缺陷发现是普遍存在于Bi 2 Te 3薄膜，七层Bi 3 Te 4纳米片受体。有趣的是，这个缺陷被发现局部拉低导带，导致局部n型导电性，尽管是一个受体，钉在附近的价带最大的费米能。这种纳米层可以解释测量的导电类型的不一致性，以及开辟了一条新的路线来操纵散装载流子浓度。我们的工作可能为更彻底地理解和定制体的性质以及为未来在量子计算和无耗散设备中的应用提供安全可控的体态铺平道路。
We present a direct atom-by-atom chemical identification of the nanostructures and defects of topological insulators (TIs) with a state-of-the-art atomic mapping technology. Combining this technique and density function theory calculations, we identify and explain the layer chemistry evolution of Bi2Te3-xSex ternary TIs. We also reveal a long neglected but crucially important extended defect found to be universally present in Bi2Te3 films, the seven layer Bi3Te4 nanolamella acceptors. Intriguingly, this defect is found to locally pull down the conduction band, leading to local n-type conductivity, despite being an acceptor which pins the Fermi energy near the valence band maximum. This nanolamella may explain inconsistencies in measured conduction type as well as open up a new route to manipulate bulk carrier concentration. Our work may pave the way to more thoroughly understand and tailor the nature of the bulk, as well as secure controllable bulk states for future applications in quantum computing and dissipationless devices.