Rehmann, Mirko K. and Kalyoncu, Yemliha B. and Kisiel, Marcin and Pascher, Nikola and Giessibl, Franz J. and Muller, Fabian and Watanabe, Kenji and Taniguchi, Takashi and Meyer, Ernst and Liu, Ming-Hao and Zumbuehl, Dominik M. (2019) Characterization of hydrogen plasma defined graphene edges. CARBON, 150. pp. 417-424. ISSN 0008-6223, 1873-3891
Full text not available from this repository. (Request a copy)Abstract
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. (C) 2019 Elsevier Ltd. All rights reserved.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | HEXAGONAL BORON-NITRIDE; ZIGZAG EDGES; SPECTROSCOPY; NANORIBBONS; QUANTUM; STATE; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Giessibl > Group Franz J. Giessibl |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 07 Apr 2020 05:14 |
| Last Modified: | 07 Apr 2020 05:14 |
| URI: | https://pred.uni-regensburg.de/id/eprint/26390 |
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