Application of tungsten as a carbon sink for synthesis of large-domain uniform monolayer graphene free of bilayers/multilayers

作者：Fang Wenjing; Hsu Allen; Shin Yong Cheol; Liao Albert; Huang Shengxi; Song Yi; Ling Xi; Dresselhaus Mildred S; Palacios Tomas; Kong Jing^*

来源：Nanoscale, 2015, 7(11): 4929-4934.

DOI：10.1039/c4nr07418a

We have found that tungsten (W) foils can be used for controlling the carbon diffusion within copper (Cu) enclosures to synthesize large-domain bi-/multi-layer-free monolayer graphene via chemical vapor deposition. We have observed that bi-/multi-layer graphene that nucleate underneath the monolayer graphene can be selectively removed by a W foil placed inside of the Cu enclosure. Both X-ray photoelectron spectroscopy and X-ray diffraction reveal the formation of tungsten sub-carbide (W2C), suggesting the role of the W foil as a carbon sink that alters the carbon concentration inside of the enclosure. Consequently, the bi-/multi-layers appear to dissolve. Utilizing this selective removal process, we were able to demonstrate large-domain (>200 mu m) monolayer graphene that is free of any bi-/multi-layers by using Cu double enclosures.

• 出版日期2015
• 单位MIT