APL Materials (May 2014)

Topological crystalline insulator PbxSn1-xTe thin films on SrTiO3 (001) with tunable Fermi levels

  • Hua Guo,
  • Chen-Hui Yan,
  • Jun-Wei Liu,
  • Zhen-Yu Wang,
  • Rui Wu,
  • Zhi-Dong Zhang,
  • Li-Li Wang,
  • Ke He,
  • Xu-Cun Ma,
  • Shuai-Hua Ji,
  • Wen-Hui Duan,
  • Xi Chen,
  • Qi-Kun Xue

DOI
https://doi.org/10.1063/1.4876637
Journal volume & issue
Vol. 2, no. 5
pp. 056106 – 056106-6

Abstract

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In this letter, we report a systematic study of topological crystalline insulator PbxSn1-xTe (0 < x < 1) thin films grown by molecular beam epitaxy on SrTiO3(001). Two domains of PbxSn1-xTe thin films with intersecting angle of α ≈ 45° were confirmed by reflection high energy diffraction, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy (ARPES). ARPES study of PbxSn1-xTe thin films demonstrated that the Fermi level of PbTe could be tuned by altering the temperature of substrate whereas SnTe cannot. An M-shaped valance band structure was observed only in SnTe but PbTe is in a topological trivial state with a large gap. In addition, co-evaporation of SnTe and PbTe results in an equivalent variation of Pb concentration as well as the Fermi level of PbxSn1-xTe thin films.