| Autor: |
Yeh, Chang, Teague, Marcus L., Boyd, David A., Bockrath, Marc W., Velasco, Jairo |
| Zdroj: |
ECS Transactions; April 2010, Vol. 28 Issue: 5 p115-123, 9p |
| Abstrakt: |
Atomically resolved imaging and spectroscopic characteristics of graphene grown by chemical vapor deposition (CVD) on copper foils are investigated and compared with those of mechanical exfoliated graphene on SiO2. For exfoliated graphene, the local spectral deviations from ideal behavior may be attributed to strain induced by the SiO2 substrate. For CVD grown graphene, the lattice structure appears strongly distorted by the underlying copper, with regions in direct contact with copper showing nearly square lattices whereas suspended regions from thermal relaxation exhibiting nearly honeycomb or hexagonal lattice structures. The electronic density of states (DOS) correlates closely with the atomic arrangements of carbon, showing excess zero-bias tunneling conductance and nearly energy-independent DOS for strongly distorted graphene, in contrast to the linearly dispersive DOS for suspended graphene. These results suggest that graphene can interact strongly with both metallic and dielectric materials in close proximity, leading to non-negligible modifications to the electronic properties. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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