Thickness-dependent bulk properties and weak antilocalization effect in topological insulator Bi2Se3
Thickness-dependent bulk properties and weak antilocalization effect in topological insulator Bi2Se3
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DOI：
10.1103/physrevb.84.073109
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发表时间：
2011-08-26
影响因子：
3.7
通讯作者：
Oh, Seongshik
中科院分区：
文献类型：
--
作者：
Kim, Yong Seung;Brahlek, Matthew;Oh, Seongshik
我们表明，拓扑绝缘体 (TI) Bi2Se3 中的许多输运特性在高达五个数量级的厚度范围（3 nm-170 μ m）内表现出惊人的厚度依赖性。体积载流子密度随着厚度的增加而降低，这可能是由于硒空位的扩散限制的形成。在薄膜状态下，迁移率随厚度线性增加，并在厚极限处饱和。微弱的反局域效应主要由厚度超过二十年的单个二维通道主导。相位相干长度的次线性厚度依赖性表明表面态和体态之间存在强耦合。
We show that a number of transport properties in topological insulator (TI) Bi2Se3 exhibit striking thickness dependences over a range of up to five orders of thickness (3 nm-170 mu m). Volume carrier density decreased with thickness, presumably due to diffusion-limited formation of selenium vacancies. Mobility increased linearly with thickness in the thin film regime and saturated in the thick limit. The weak antilocalization effect was dominated by a single two-dimensional channel over two decades of thickness. The sublinear thickness-dependence of the phase coherence length suggests the presence of strong coupling between the surface and bulk states.