High-Yield Chemical Vapor Deposition Growth of High-Quality Large-Area AB-Stacked Bilayer Graphene

 作 者

 摘 要

Bernal-stacked (AB-stacked) bilayer graphene is of significant interest for functional electronic and photonic devices due to the feasibility to continuously tune its band gap with a vertical electric field. Mechanical exfoliation can be used to produce AB-stacked bilayer graphene flakes but typically with the sizes limited to a few micrometers. Chemical vapor deposition (CVD) has been recently explored for the synthesis of bilayer graphene but usually with limited coverage and a mixture of AB- and randomly stacked structures. Herein we report a rational approach to produce large-area high-quality AB-stacked bilayer graphene. We show that the self-limiting effect of graphene growth on Cu foil can be broken by using a high H₂/CH₄ ratio in a low-pressure CVD process to enable the continued growth of bilayer graphene. A high-temperature and low-pressure nucleation step is found to be critical for the formation of bilayer graphene nuclei with high AB stacking ratio. A rational design of a two-step CVD process is developed for the growth of bilayer graphene with high AB stacking ratio (up to 90%) and high coverage (up to 99%). The electrical transport studies demonstrate that devices made of the as-grown bilayer graphene exhibit typical characteristics of AB-stacked bilayer graphene with the highest carrier mobility exceeding 4000 cm²/V·s at room temperature, comparable to that of the exfoliated bilayer graphene.

 详细资料

• 文献种类:期刊
• 期刊名称: ACS Nano
• 期刊缩写: ACS Nano
• 期卷页: 2012年  第6卷 第9期 8241-8249页
• ISBN: 1936-0851

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