MBE Growth and Characterization of Strained HgTe (111) Films on CdTe/GaAs
MBE Growth and Characterization of Strained HgTe (111) Films on CdTe/GaAs
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CdTe/GaAs 上应变 HgTe (111) 薄膜的 MBE 生长和表征
DOI：
10.1088/0256-307x/37/3/038101
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发表时间：
2020
影响因子：
3.5
通讯作者：
Chen Pingping
中科院分区：
文献类型：
--
作者：
Zhang Jian;Zhang Shengxi;Qiu Xiaofang;Wu Yan;Sun Qiang;Zou Jin;Li Tianxin;Chen Pingping
应变碲化汞薄膜是典型的三维拓扑绝缘体材料。由于HgTe（100）薄膜的单轴应变导致的拓扑性质，大部分工作都集中在HgTe（100）薄膜上。本研究利用分子束磊晶技术，以碲化镉（111）为缓冲层，在砷化镓（100）基底上成长应变碲化汞（111）薄膜。HgTe薄膜的最佳生长条件确定为生长温度为160°C，Hg/Te流量比为200。用高分辨X射线衍射法研究了不同厚度碲化汞薄膜的应变，包括倒易空间映射测量。利用马修斯公式计算了CdTe/GaAs上HgTe（111）薄膜的临界厚度约为284 nm，与实验结果一致。反射高能电子衍射和高分辨透射电子显微镜的研究表明，高质量的碲化汞薄膜获得。分子束外延生长碲化汞（111）薄膜的探索为碲化汞拓扑绝缘体的进一步研究提供了有价值的信息。
Strained HgTe thin films are typical three-dimensional topological insulator materials. Most works have focused on HgTe (100) films due to the topological properties resulting from uniaxial strain. In this study, strained HgTe (111) thin films are grown on GaAs (100) substrates with CdTe (111) buffer layers using molecular beam epitaxy (MBE). The optimal growth conditions for HgTe films are determined to be a growth temperature of 160°C and an Hg/Te flux ratio of 200. The strains of HgTe films with different thicknesses are investigated by high-resolution x-ray diffraction, including reciprocal space mapping measurements. The critical thickness of HgTe (111) film on CdTe/GaAs is estimated to be approximately 284 nm by Matthews’ equations, consistent with the experimental results. Reflection high-energy electron diffraction and high-resolution transmission electron microscopy investigations indicate that high-quality HgTe films are obtained. This exploration of the MBE growth of HgTe (111) films provides valuable information for further studies of HgTe-based topological insulators.