Graphene Formation on Step-free 4H-SiC(0001)
Step-free SiC was thermally decomposed in vacuum to better understand graphene formation in the absence of step fronts. Atomic force microscopy revealed graphene nucleating at surface pits that preferentially form along SiC{l_brace}1{bar 1}00{r_brace} planes. The density of these pits is 1 x 10{sup 8} cm{sup -2}, which is three orders of magnitude greater than the measured density of SiC threading dislocations. Additionally, Raman spectroscopy demonstrated that graphene on step-free regions have a redshifted 2D peak position and a smaller peak width than does graphene grown on stepped regions. This difference is attributed to film thickness, which is confirmed by cross-sectional transmission electron microscopy. Stepped regions have a graphitic film nearly 2 nm thick as compared to less than 0.7 nm for step-free regions.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). Center for Functional Nanomaterials (CFN)
- Sponsoring Organization:
- US DEPARTMENT OF DEFENSE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1041593
- Report Number(s):
- BNL-96645-2011-JA; JAPIAU; R&D Project: NC-001; TRN: US201212%%11
- Journal Information:
- Journal of Applied Physics, Vol. 110, Issue 7; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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