In situ Raman spectroscopy of topological insulator Bi2Te3 films with varying thickness
In situ Raman spectroscopy of topological insulator Bi2Te3 films with varying thickness
复制标题
不同厚度拓扑绝缘体 Bi2Te3 薄膜的原位拉曼光谱
DOI：
10.1007/s12274-013-0344-4
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发表时间：
2013-09-01
期刊：
影响因子：
9.9
通讯作者：
Xue, Qikun
中科院分区：
文献类型：
--
作者：
Wang, Chunxiao;Zhu, Xiegang;Xue, Qikun
拓扑绝缘体(TIS)是一种具有体态和导电表面态带隙的新型量子物质。用超高真空分子束外延(MBE)原位拉曼光谱系统测量了分子束外延(MBE)制备的拓扑绝缘体Bi2Te3薄膜的拉曼光谱。当Bi2Te3薄膜的厚度从40个五层(QL)减小到1QL时，块体Bi2Te3中出现的一些喇曼模式的光谱特性发生了变化，出现了一个新的振动模式，这可能与量子尺寸效应和对称性破缺有关，在以往的研究中没有报道过。此外，当Dirac锥形成时，在3QL观察到明显的变化。这些结果为TIS的新量子态提供了一些新的信息。
AbstractTopological insulators (TIs) are a new state of quantum matter with a band gap in bulk and conducting surface states. In this work, the Raman spectra of topological insulator Bi2Te3 films prepared by molecular beam epitaxy (MBE) have been measured by an in situ ultrahigh vacuum (UHV)-MBE-Raman spectroscopy system. When the thickness of Bi2Te3 films decreases from 40 quintuple-layers (QL) to 1 QL, the spectral characteristics of some Raman modes appearing in bulk Bi2Te3 vary and a new vibrational mode appears, which has not been reported in previous studies and might be related to quantum size effects and symmetry breaking. In addition, an obvious change was observed at 3 QL when a Dirac cone formed. These results offer some new information about the novel quantum states of TIs.