• 文献标题:   Silicon Carbide Stacking-Order-Induced Doping Variation in Epitaxial Graphene
  • 文献类型:   Article
  • 作  者:   PAKDEHI DM, SCHADLICH P, NGUYEN TTN, ZAKHAROV AA, WUNDRACK S, NAJAFIDEHAGHANI E, SPECK F, PIERZ K, SEYLLER T, TEGENKAMP C, SCHUMACHER HW
  • 作者关键词:   epitaxial graphene, hexagonal silicon carbide, sic spontaneous polarization, surfacedependent polarization doping
  • 出版物名称:   ADVANCED FUNCTIONAL MATERIALS
  • ISSN:   1616-301X EI 1616-3028
  • 通讯作者地址:   Phys Tech Bundesanstalt
  • 被引频次:   1
  • DOI:   10.1002/adfm.202004695 EA SEP 2020
  • 出版年:   2020

▎ 摘  要

Generally, it is supposed that the Fermi level in epitaxial graphene is controlled by two effects: p-type polarization doping induced by the bulk of the hexagonal silicon carbide (SiC)(0001) substrate and overcompensation by donor-like states related to the buffer layer. The presented work is evidence that this effect is also related to the specific underlying SiC terrace. Here a periodic sequence of non-identical SiC terraces is fabricated, which are unambiguously attributed to specific SiC surface terminations. A clear correlation between the SiC termination and the electronic graphene properties is experimentally observed and confirmed by various complementary surface-sensitive methods. This correlation is attributed to a proximity effect of the SiC termination-dependent polarization doping on the overlying graphene layer. These findings open a new approach for a nano-scale doping-engineering by the self-patterning of epitaxial graphene and other 2D layers on dielectric polar substrates.