Abstract
The purity of graphene samples is of crucial importance for their experimental and practical use. In this regard, the detection of the defects is of direct relevance. Here, we show that structural defects in graphene samples give rise to clear signals in the vibrational density of states (VDOS) at specific peaks at high and low frequencies. These can be used as an independent probe of the defect density. In particular, we consider grain boundaries made of pentagon-heptagon pairs, and show that they lead to a shift of the characteristic vibrational D mode toward higher frequency; this distinguishes these line defects from Stone Wales point defects, which do not lead to such a shift. Our findings may be instrumental for the detection of structural lattice defects using experimental techniques that can directly measure VDOS, such as inelastic electron tunneling and inelastic neutron spectroscopy.
| Original language | English |
|---|---|
| Pages (from-to) | 3897-3902 |
| Number of pages | 6 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 6 |
| Issue number | 19 |
| DOIs | |
| Publication status | Published - 1 Oct 2015 |
Funding
We acknowledge the financial support by the FOM-SHELL-CSER program (12CSER049). This work is part of the research program of the Foundation for Fundamental Research of Matter (FOM), which is part of The Netherlands Organisation for Scientific Research (NWO). We would like to thank Ingmar Swart and Rembert Duine for useful discussions.
Keywords
- CARBON NANOTUBES
- CHEMICAL FUNCTIONALIZATION
- SUSPENDED GRAPHENE
- STRUCTURAL DEFECTS
- GRAIN-BOUNDARIES
- SUBSTRATE
- RAMAN
- SPECTROSCOPY
- SINGLE
- MICROSCOPY