Quantitative Analysis of Graphene Doping by Organic Molecular Charge Transfer

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• 作者：Xiaomu Wang ; Jian-Bin Xu ; Weiguang Xie ; Jun Du
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：April 21, 2011
• 年：2011
• 卷：115
• 期：15
• 页码：7596-7602
• 全文大小：958K
• 年卷期：v.115,no.15(April 21, 2011)
• ISSN：1932-7455

文摘

In this paper, both n-type and p-type doped exfoliated graphene sheets are presented by virtue of adsorbing organic molecules. Flat organic layers are uniformly grown on graphene sheets by the technique. Meanwhile, the high-mobility attribute of graphene is largely preserved, as adsorption on the graphene surface does not significantly modify the 蟺-bonding networks of graphene. By employing Kelvin probe force microscopy, we show that the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) molecules obtain electrons from graphene whereas vanadyl鈭抪hthalocyanine (VOPc) molecules donate electrons to it. The amount of charge transfer by F4-TCNQ and VOPc to bilayer graphene on silicon dioxide substrate is estimated to be approximately 0.4 and 0.1 electron/molecule by a tight-binding self-consistent model, respectively. The consistent theoretical and experimental results demonstrate that doping of graphene by organic molecular charge transfer has great implications for future large-scale applications of graphene-based nanoelectronics.