Single-layer dual germanene phases on Ag(111)

Chung Huang Lin, Angus Huang, Woei Wu Pai, Wei Chuan Chen, Ting Yu Chen, Tay Rong Chang, Ryu Yukawa, Cheng Maw Cheng, Chung Yu Mou, Iwao Matsuda, T. C. Chiang, H. T. Jeng, S. J. Tang

研究成果: Article

23 引文 斯高帕斯(Scopus)

摘要

Two-dimensional (2D) honeycomb lattices beyond graphene promise new physical properties such as quantum spin Hall effect. While there have been claims of growth of such lattices (silicene, germanene, stanene), their existence needs further support and their preparation and characterization remain a difficult challenge. Our findings suggest that two distinct phases associated with germanene, the analog of graphene made of germanium (Ge) instead of carbon, can be grown on Ag(111) as observed by scanning tunneling microscopy, low-energy electron diffraction, and angle-resolved photoemission spectroscopy. One such germanene exhibits an atom-resolved alternatively buckled full honeycomb lattice, which is tensile strained and partially commensurate with the substrate to form a striped phase (SP). The other, a quasifreestanding phase (QP), is also consistent with a honeycomb lattice with a lattice constant incommensurate with the substrate but very close to the theoretical value for freestanding germanene. The SP, with a lower atomic density, can be driven into the QP and coexist with the QP by additional Ge deposition. Band mapping and first-principles calculations with proposed SP and QP models reveal an interface state exists only in the SP but the characteristic σ band of freestanding germanene emerges only in the QP - this leads to an important conclusion that adlayer-substrate commensurability plays a key role to affect the electronic structure of germanene. The evolution of the dual germanene phases manifests the competitive formation of Ge-Ge covalent and Ge-Ag interfacial bonds.

原文English
文章編號024003
期刊Physical Review Materials
2
發行號2
DOIs
出版狀態Published - 2018 二月 9

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

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    Lin, C. H., Huang, A., Pai, W. W., Chen, W. C., Chen, T. Y., Chang, T. R., Yukawa, R., Cheng, C. M., Mou, C. Y., Matsuda, I., Chiang, T. C., Jeng, H. T., & Tang, S. J. (2018). Single-layer dual germanene phases on Ag(111). Physical Review Materials, 2(2), [024003]. https://doi.org/10.1103/PhysRevMaterials.2.024003