Chemical Vapor Deposition of Graphene on Copper from Methane, Ethane and Propane: Evidence for Bilayer Selectivity

Abstract

To study the effects of hydrocarbon precursor gases, graphene is grown by chemical vapor deposition from methane, ethane, and propane on copper foils. The larger molecules are found to more readily produce bilayer and multilayer graphene, due to a higher carbon concentration and different decomposition processes. Single- and bilayer graphene can be grown with good selectivity in a simple, single-precursor process by varying the pressure of ethane from 250 to 1000 mTorr. The bilayer graphene is AB-stacked as shown by selected area electron diffraction analysis. Additionally propane is found to only produce a combination of single- to few-layer and turbostratic graphene. The percent coverage is investgated using Raman spectroscopy and optical, scanning electron, and transmission electron microscopies. The data are used to discuss a possible mechanism for the second-layer growth of graphene involving the different cracking pathways of the hydrocarbons.

A simple method to tune graphene growth between monolayer and bilayer

“…In contrast, graphene grown on copper is typically monolayer due to the "self-limiting" effect 30 Cu-Ni alloy has been used to grow bilayer graphene [6][7][8] by carefully adjusting the atomic percentage. Recently, researchers have also grown bilayer graphene on copper by regulating various conditions including the carbon source, 9,10 copper purity, 11,12 pressure, 13 growth temperature 14 and gas flow rate. 15 However, these methods either require much prolonged growth processes or produce bilayer films which are not continuous because the second layer is much smaller than the first.…”

Graphene NanoPlatelets Reinforced Tantalum Carbide consolidated by Spark Plasma Sintering

“…Wassei et al [83] The characterization of graphene presents novel challenges because of the unique size and geometry. This thesis focuses on the use of graphene for structural composites and thus the characterization of graphene structure and mechanical properties are of utmost importance.…”

Graphene synthesis: a Review

“…It is possible to grow large films of graphene using this method [87,90,91]. In contrast to methane gas, ethane and propane tend to produce bilayer coatings; this could be due to their molecular structure containing a higher concentration of carbon [92].…”