Restoring self-limited growth of single-layer graphene on copper foil via backside coating

TL;DR

This paper presents a novel backside tungsten coating method for copper foil that enables consistent single-layer graphene growth via atmospheric pressure CVD without complex controls, improving reproducibility and scalability.

Contribution

The study introduces a simple backside coating technique that suppresses multilayer graphene formation, enhancing the reproducibility and efficiency of large-scale single-layer graphene production.

Findings

Backside tungsten coating prevents multilayer graphene patches.

The method allows full coverage growth with shorter process times.

No need for tight hydrocarbon flow control.

Abstract

The growth of single-layer graphene (SLG) by chemical vapor deposition (CVD) on copper surfaces is very popular because of the self-limiting effect that prevents the growth of few-layer graphene (FLG). However, the reproducibility of the CVD growth of homogeneous SLG remains a major challenge, especially if one wants to avoid heavy surface treatments, monocrystalline substrates and expensive equipment to control the atmosphere inside the growth system. We demonstrate here that backside tungsten coating of copper foil allows the exclusive growth of SLG with full coverage by atmospheric pressure CVD implemented in a vacuum-free outfit. We show that the absence of FLG patches is related to the absence of decomposition of methane on the backside and consequently to the suppression of C diffusion through copper. In the perspective of large-scale production of graphene, this approach constitutes a significant improvement to the traditional CVD growth process since (1) a tight control of the hydrocarbon flow is no longer required to avoid FLG formation and, consequently, (2) the growth duration necessary to reach full coverage can be dramatically shortened.