• 文献标题:   Diffraction paradox: An unusually broad diffraction background marks high quality graphene
  • 文献类型:   Article
  • 作  者:   CHEN S, VON HOEGEN MH, THIEL PA, TRINGIDES MC
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   US DOE
  • 被引频次:   0
  • DOI:   10.1103/PhysRevB.100.155307
  • 出版年:   2019

▎ 摘  要

The realization of the unusual properties of two-dimensional (2D) materials requires the formation of large domains of single-layer thickness, extending over the mesoscale. It is found that the formation of uniform graphene on SiC, contrary to textbook diffraction, is signaled by a strong bell-shaped component (BSC) around the (00) and G(10) spots (but not around the substrate spots). The BCS is also seen on graphene grown on metals, because a single uniform graphene layer can be also grown with large lateral size. It is only seen by electron diffraction but not with x-ray or He scattering. Although the origin of such an intriguing result is unclear, its presence in the earlier literature (but never mentioned) points to its robustness and significance. A likely mechanism relates to the the spatial confinement of the graphene electrons, within a single layer. This leads to large spread in their wave vector which is transferred by electron-electron interactions to the elastically scattered electrons to generate the BSC.