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Title: Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape

Abstract

The initial stages of graphene chemical vapor deposition at very low pressures (<10{sup −5 }Torr) were investigated. The growth of large graphene domains (∼up to 100 μm) at very high rates (up to 3 μm{sup 2} s{sup −1}) has been achieved in a cold-wall reactor using a liquid carbon precursor. For high temperature growth (>900 °C), graphene grain shape and symmetry were found to depend on the underlying symmetry of the Cu crystal, whereas for lower temperatures (<900 °C), mostly rounded grains are observed. The temperature dependence of graphene nucleation density was determined, displaying two thermally activated regimes, with activation energy values of 6 ± 1 eV for temperatures ranging from 900 °C to 960 °C and 9 ± 1 eV for temperatures above 960 °C. The comparison of such dependence with the temperature dependence of Cu surface self-diffusion suggests that graphene growth at high temperatures and low pressures is strongly influenced by copper surface rearrangement. We propose a model that incorporates Cu surface self-diffusion as an essential process to explain the orientation correlation between graphene and Cu crystals, and which can clarify the difference generally observed between graphene domain shapes in atmospheric-pressure and low-pressure chemical vapor deposition.

Authors:
; ; ;  [1]
  1. Department of Physics, Federal University of Minas Gerais, Belo Horizonte 31270-901 (Brazil)
Publication Date:
OSTI Identifier:
22310904
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACTIVATION ENERGY; ATMOSPHERIC PRESSURE; CHEMICAL VAPOR DEPOSITION; COPPER; CORRELATIONS; CRYSTAL GROWTH; CRYSTALS; DENSITY; EV RANGE; GRAPHENE; SELF-DIFFUSION; SUBSTRATES; SURFACES; SYMMETRY; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 1000-4000 K

Citation Formats

Cunha, T. H. R., Ek-Weis, J., Lacerda, R. G., and Ferlauto, A. S., E-mail: ferlauto@fisica.ufmg.br. Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape. United States: N. p., 2014. Web. doi:10.1063/1.4893696.
Cunha, T. H. R., Ek-Weis, J., Lacerda, R. G., & Ferlauto, A. S., E-mail: ferlauto@fisica.ufmg.br. Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape. United States. doi:10.1063/1.4893696.
Cunha, T. H. R., Ek-Weis, J., Lacerda, R. G., and Ferlauto, A. S., E-mail: ferlauto@fisica.ufmg.br. Mon . "Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape". United States. doi:10.1063/1.4893696.
@article{osti_22310904,
title = {Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape},
author = {Cunha, T. H. R. and Ek-Weis, J. and Lacerda, R. G. and Ferlauto, A. S., E-mail: ferlauto@fisica.ufmg.br},
abstractNote = {The initial stages of graphene chemical vapor deposition at very low pressures (<10{sup −5 }Torr) were investigated. The growth of large graphene domains (∼up to 100 μm) at very high rates (up to 3 μm{sup 2} s{sup −1}) has been achieved in a cold-wall reactor using a liquid carbon precursor. For high temperature growth (>900 °C), graphene grain shape and symmetry were found to depend on the underlying symmetry of the Cu crystal, whereas for lower temperatures (<900 °C), mostly rounded grains are observed. The temperature dependence of graphene nucleation density was determined, displaying two thermally activated regimes, with activation energy values of 6 ± 1 eV for temperatures ranging from 900 °C to 960 °C and 9 ± 1 eV for temperatures above 960 °C. The comparison of such dependence with the temperature dependence of Cu surface self-diffusion suggests that graphene growth at high temperatures and low pressures is strongly influenced by copper surface rearrangement. We propose a model that incorporates Cu surface self-diffusion as an essential process to explain the orientation correlation between graphene and Cu crystals, and which can clarify the difference generally observed between graphene domain shapes in atmospheric-pressure and low-pressure chemical vapor deposition.},
doi = {10.1063/1.4893696},
journal = {Applied Physics Letters},
number = 7,
volume = 105,
place = {United States},
year = {Mon Aug 18 00:00:00 EDT 2014},
month = {Mon Aug 18 00:00:00 EDT 2014}
}