Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils

TL;DR

This paper reports the large-area synthesis of high-quality, uniform graphene films on copper foils via chemical vapor deposition, demonstrating their transferability and high electron mobility in fabricated transistors.

Contribution

It introduces a scalable method for producing large, uniform graphene films on copper and demonstrates their transfer and electronic properties.

Findings

Graphene films are predominantly single-layer over centimeters.

Transferred graphene exhibits electron mobilities up to 4050 cm2V-1s-1.

Growth process is self-limiting due to low carbon solubility in copper.

Abstract

Graphene has been attracting great interest because of its distinctive band structure and physical properties. Today, graphene is limited to small sizes because it is produced mostly by exfoliating graphite. We grew large-area graphene films of the order of centimeters on copper substrates by chemical vapor deposition using methane. The films are predominantly single layer graphene with a small percentage (less than 5%) of the area having few layers, and are continuous across copper surface steps and grain boundaries. The low solubility of carbon in copper appears to help make this growth process self-limiting. We also developed graphene film transfer processes to arbitrary substrates, and dual-gated field-effect transistors fabricated on Si/SiO2 substrates showed electron mobilities as high as 4050 cm2V-1s-1 at room temperature.