Characterization of hydrogen plasma defined graphene edges

Mirko K. Rehmann, Yemliha B. Kalyoncu, Marcin Kisiel, Nikola Pascher, Franz J. Giessibl, Fabian Müller, Kenji Watanabe, Takashi Taniguchi, Ernst Meyer, Ming Hao Liu, Dominik M. Zumbühl

研究成果: Article同行評審

7 引文 斯高帕斯(Scopus)


We investigate the quality of hydrogen plasma defined graphene edges by Raman spectroscopy, atomic resolution AFM and low temperature electronic transport measurements. The exposure of graphite samples to a remote hydrogen plasma leads to the formation of hexagonal shaped etch pits, reflecting the anisotropy of the etch. Atomic resolution AFM reveals that the sides of these hexagons are oriented along the zigzag direction of the graphite crystal lattice and the absence of a D-peak within the noise background in the Raman spectra seems to suggest rather high quality zigzag edges. In a second step of the experiment, we investigate hexagon edges created in single layer graphene on hexagonal boron nitride and find a substantial D-peak intensity. Polarization dependent Raman measurements reveal that hydrogen plasma defined edges consist of a mixture of zigzag and armchair segments. Furthermore, electronic transport measurements were performed on hydrogen plasma defined graphene nanoribbons which indicate a high quality of the bulk but a relatively low edge quality, in agreement with the Raman data. These findings are supported by tight-binding transport simulations. Hence, further optimization of the hydrogen plasma etching technique is required to obtain pure crystalline graphene edges.

頁(從 - 到)417-424
出版狀態Published - 2019 9月

All Science Journal Classification (ASJC) codes

  • 一般化學
  • 一般材料科學


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