Growth Mechanism and Controlled Synthesis of AB-Stacked Bilayer Graphene on Cu鈥揘i Alloy Foils
详细信息 查看全文
- 作者：Yaping Wu ; Harry Chou ; Hengxing Ji ; Qingzhi Wu ; Shanshan Chen ; Wei Jiang ; Yufeng Hao ; Junyong Kang ; Yujie Ren ; Richard D. Piner ; Rodney S. Ruoff
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：September 25, 2012
- 年：2012
- 卷：6
- 期：9
- 页码：7731-7738
- 全文大小：532K
- 年卷期：v.6,no.9(September 25, 2012)
- ISSN：1936-086X
文摘
Strongly coupled bilayer graphene (i.e., AB stacked) grows particularly well on commercial 鈥?0鈥?0鈥?Cu鈥揘i alloy foil. However, the mechanism of growth of bilayer graphene on Cu鈥揘i alloy foils had not been discovered. Carbon isotope labeling (sequential dosing of 12CH4 and 13CH4) and Raman spectroscopic mapping were used to study the growth process. It was learned that the mechanism of graphene growth on Cu鈥揘i alloy is by precipitation at the surface from carbon dissolved in the bulk of the alloy foil that diffuses to the surface. The growth parameters were varied to investigate their effect on graphene coverage and isotopic composition. It was found that higher temperature, longer exposure time, higher rate of bulk diffusion for 12C vs13C, and slower cooling rate all produced higher graphene coverage on this type of Cu鈥揘i alloy foil. The isotopic composition of the graphene layer(s) could also be modified by adjusting the cooling rate. In addition, large-area, AB-stacked bilayer graphene transferrable onto Si/SiO2 substrates was controllably synthesized.