物理化学学报 >> 2017, Vol. 33 >> Issue (2): 419-425.doi: 10.3866/PKU.WHXB201610192

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PbTe (111)薄膜的分子束外延生长及其表面结构特性

吴海飞1,*(),陈耀1,徐珊瑚1,鄢永红1,斯剑霄2,谭永胜1   

  1. 1 绍兴文理学院物理系,浙江绍兴312000
    2 浙江师范大学数理与信息工程学院,浙江金华312004
  • 收稿日期:2016-08-09 发布日期:2017-01-12
  • 通讯作者: 吴海飞 E-mail:wuhaifei@usx.edu.cn
  • 基金资助:
    国家自然科学基金(51202149,51302248,11575116,61405118)

Molecular Beam Epitaxy Growth and Surface Structural Characteristics of PbTe(111) Thin Film

Hai-Fei WU1,*(),Yao CHEN1,Shan-Hu XU1,Yong-Hong YAN1,Jian-Xiao SI2,Yong-Sheng TAN1   

  1. 1 Department of Physics, Shaoxing University, Shaoxing 312000, Zhejiang Province, P. R. China
    2 College of Mathematics, Physics and Information Engineering, Zhejiang Normal University, Jinhua 312004, Zhejiang Province, P. R. China
  • Received:2016-08-09 Published:2017-01-12
  • Contact: Hai-Fei WU E-mail:wuhaifei@usx.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(51202149,51302248,11575116,61405118)

摘要:

采用分子束外延(MBE)方法在BaF2(111)衬底上直接外延生长了PbTe薄膜。反射高能电子衍射(RHEED)实时监控的衍射图样揭示了PbTe在BaF2(111)表面由三维生长向二维生长的变化过程。转动对称性的研究结合第一性原理密度泛函理论(DFT)的计算揭示了在富Pb及衬底温度(Tsub)为350℃的生长条件下,得到的PbTe(111)薄膜具有稳定的(2×1)重构表面。PbTe(111)-(2×1)表面覆盖Te膜后,通过300℃的退火处理,重构表面可完全复原,这为大气环境下PbTe薄膜表面结构的保护提供了有效的方法。

关键词: 表面重构, DFT, RHEED, 转动对称性, PbTe薄膜

Abstract:

PbTe thin films were epitaxially grown on BaF2(111) substrate using molecular beam epitaxy (MBE). In situ characterization by reflection high energy electron diffraction (RHEED) revealed a transition of the growth mode from 3D to 2D. Rotational symmetry studies combined with first principles density functional theory (DFT) calculations revealed that under Pb-rich and 350℃ substrate temperature (Tsub) growth conditions, stable (2×1) reconstructions appear on the PbTe(111) surface. When the surface of PbTe(111)-(2×1) was covered with Te, the stable (2×1) reconstructions could be retrieved under 300℃ annealing. This provides an effective method for the protection of PbTe film surfaces from the atmospheric environment.

Key words: Surface reconstruction, DFT, RHEED, Rotational symmetry, PbTe thin film