Graphene Segregated on Ni surfaces and Transferred to Insulators

TL;DR

This paper presents a method for synthesizing high-quality graphene via surface segregation on Ni and transfer to insulators, emphasizing the influence of cooling rates on film quality and structure.

Contribution

It introduces a novel high-temperature segregation and transfer process for graphene, with detailed control over film quality through cooling rate adjustments.

Findings

Medium cooling rates produce high-quality crystalline graphene.

Transferred graphene maintains quality on insulating substrates.

Cooling rate significantly affects graphene thickness and structure.

Abstract

We report an approach to synthesize high quality graphene by surface segregation and substrate transfer. Graphene was segregated from Ni surface under the ambient pressure by dissolving carbon in Ni at high temperatures followed by cooling down with various rates. Different cooling rates led to different segregation behaviors, strongly affecting the thickness and quality of the graphene films. Electron microscopy and Raman spectroscopy indicated that the graphene films synthesized with medium cooling rates have high quality crystalline structure and well-controlled thicknesses. The graphene films were transferred to insulating substrates by wet etching and found to maintain their high quality.