Effect of copper surface pre-treatment on the properties of CVD grown graphene

Abstract

Here, we report the synthesis of high quality monolayer graphene on the pre-treated copper (Cu) foil by chemical vapor deposition method. The pre-treatment process, which consists of pre-annealing in a hydrogen ambient, followed by diluted nitric acid etching of Cu foil, helps in removing impurities. These impurities include native copper oxide and rolling lines that act as a nucleation center for multilayer graphene. Raman mapping of our graphene grown on pre-treated Cu foil primarily consisted of ∼98% a monolayer graphene with as compared to 75 % for the graphene grown on untreated Cu foil. A high hydrogen flow rate during the pre-annealing process resulted in an increased I2D/IG ratio of graphene up to 3.55. Uniform monolayer graphene was obtained with a I2D/IG ratio and sheet resistance varying from 1.84 – 3.39 and 1110 – 1290 Ω/□, respectively.

Unveiling the Direct Correlation between the CVD-Grown Graphene and the Growth Template

“…Among these various approaches in the CVD process, modifying the surface morphologies of catalytic growth substrates is considered one of the most viable approaches for obtaining high-quality graphene. Mechanical or chemical treatments are typically used in such approach which significantly reduces the impurities present in the metal catalysts, the major source of the nucleation center, leading to the improved carrier mobility [26][27][28][29][30][31][32]. In this work, we revisit the role of surface morphology of metal catalyst to the quality of CVD graphene using commercially available copper foil via simple chemical treatments and analyze the resulting physical properties.…”

Preparation of Few-Layer Graphene by Pulsed Discharge in Graphite Micro-Flake Suspension

“…1 and 2), the sizes of observed graphene nanosheets (Figure 3a Raman spectroscopy is very informative and sensitive for studying carbon materials [36]. It provides a quick and facile identification of carbon materials [21,23,37,38], which is a significant method to identify graphene. As shown in Figure 4, three characteristic bands are observed in each Raman spectrum, including D band (approximate 1340 cm −1 ), G band (approximate 1580 cm −1 ) and 2D band (approximate 2660 cm −1 ).…”

Acetic Acid and Ammonium Persulfate Pre-Treated Copper Foil for the Improvement of Graphene Quality, Sensitivity and Specificity of Hall Effect Label-Free DNA Hybridization Detection

“…They synthesized high quality and uniform graphene on Cu by this method which can effectively reduce the impurities on Cu. Raman mapping results showed that 98.3% of the mapped area exhibited monolayer characteristics with I 2D /I G > 2 compared to 75% monolayer characteristics for that grown on untreated Cu foil [34]. Jeong H, et al used ammonium persulfate solution combined with gentle ultrasonication (100 W) to remove the impurities on copper foil.…”