Visualizing topological insulating Bi2Te3 quintuple layers on SiO2-capped Si substrates and its contrast optimization.
Visualizing topological insulating Bi2Te3 quintuple layers on SiO2-capped Si substrates and its contrast optimization.
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DOI：
10.1166/jnn.2011.4205
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发表时间：
2010-08
影响因子：
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通讯作者：
Zhaoguo Li;Yuyuan Qin;Yuewen Mu;Taishi Chen;Changhui Xu;Longbing He;J. Wan;F. Song;Jianfeng Zhou;Min Han;Guanghou Wang
中科院分区：
文献类型：
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作者：
Zhaoguo Li;Yuyuan Qin;Yuewen Mu;Taishi Chen;Changhui Xu;Longbing He;J. Wan;F. Song;Jianfeng Zhou;Min Han;Guanghou Wang
薄Bi2Te3薄片，少至3个五重层，在SiO2覆盖的Si衬底上光学可视化。它们的光学对比度随照明波长、薄片厚度和覆盖层而变化。最大对比度出现在具有570 nm波长的优化光处。当薄片减少到少于20个五重层时，对比度反转。基于菲涅耳定律的计算描述了上述观察与层数波长对比度三维（3D）图和帽厚度波长对比度3D图的构造，适用于当前的拓扑绝缘薄片的研究。
Thin Bi2Te3 flakes, with as few as 3 quintuple layers, are optically visualized on the SiO2-capped Si substrates. Their optical contrasts vary with the illumination wavelength, flake thickness and capping layers. The maximum contrast appears at the optimized light with the 570 nm wavelength. The contrast turns reversed when the flake is reduced to less than 20 quintuple layers. A calculation based on the Fresnel law describes the above observation with the constructions of the layer number-wave length-contrast three-dimensional (3D) diagram and the cap thickness-wavelength-contrast 3D diagram, applicative in the current studies of topological insulating flakes.