title   
  

Spontaneous nucleation and growth of graphene flakes on copper foil in the absence of external carbon precursor in chemical vapor deposition

Khaksaran, Mohammad Hadi and Kaya, İsmet İnönü (2018) Spontaneous nucleation and growth of graphene flakes on copper foil in the absence of external carbon precursor in chemical vapor deposition. ACS Omega, 3 (10). pp. 12575-12583. ISSN 2470-1343

Full text not available from this repository.

Official URL: http://dx.doi.org/10.1021/acsomega.8b01652

Abstract

In this work, we uncover a mechanism initiating spontaneous nucleation of graphene flakes on copper foil during the annealing phase of chemical vapor deposition (CVD) process. We demonstrate that the carbon in the bulk of copper foil is the source of nucleation. Although carbon solubility in a pure copper bulk is very low, excess carbon can be embedded inside the copper foil during the foil production process. Using time-of-flight secondary ion mass spectrometry, we measured the distribution profile of carbon atoms inside the copper foils and its variation by thermal annealing. We also studied the role of hydrogen in the segregation of carbon from the bulk to the surface of copper during annealing by scanning electron microscopy and Raman analysis. We found that carbon atoms diffuse out from the copper foil and accumulate on its surface during annealing in the presence of hydrogen. Consequently, graphene crystals can be nucleated and grown while "any external" carbon precursor was entirely avoided. To our knowledge, this is the first time that such growth has been demonstrated to take place. We believe that this finding brings a new insight into the initial nucleation of graphene in the CVD process and helps to achieve reproducible growth recipes.

Item Type:Article
Uncontrolled Keywords:CVD, graphene, carbon, copper
Subjects:Q Science > QC Physics > QC176-176.9 Solids. Solid state physics
ID Code:36784
Deposited By:İsmet İnönü Kaya
Deposited On:07 Jan 2019 15:30
Last Modified:07 Jan 2019 15:30

Repository Staff Only: item control page