• 文献标题:   Systematic Doping Control of CVD Graphene Transistors with Functionalized Aromatic Self-Assembled Monolayers
  • 文献类型:   Article
  • 作  者:   CERNETIC N, WU SF, DAVIES JA, KRUEGER BW, HUTCHINS DO, XU XD, MA H, JEN AKY
  • 作者关键词:   graphene, selfassembled monolayer, field effect transistor, doping, phosphonic acid
  • 出版物名称:   ADVANCED FUNCTIONAL MATERIALS
  • ISSN:   1616-301X EI 1616-3028
  • 通讯作者地址:   Univ Washington
  • 被引频次:   33
  • DOI:   10.1002/adfm.201303952
  • 出版年:   2014

▎ 摘  要

Recent reports have shown that self-assembled monolayers (SAMs) can induce doping effects in graphene transistors. However, a lack of understanding persists surrounding the quantitative relationship between SAM molecular design and its effects on graphene. In order to facilitate the fabrication of next-generation graphene-based devices it is important to reliably and predictably control the properties of graphene without negatively impacting its intrinsic high performance. In this study, SAMs with varying dipole magnitudes/directions are utilized and these values are directly correlated to changes in performance seen in graphene transistors. It is found that, by knowing the z-component of the SAM dipole, one can reliably predict the shift in graphene charge neutrality point after taking into account the influence of the metal electrodes (which also play a role in doping graphene). This relationship is verified through density functional theory and comprehensive device studies utilizing atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and electrical characterization of graphene transistors. It is shown that properties of graphene transistors can be predictably controlled with SAMs when considering the total doping environment. Additionally, it is found that methylthio-terminated SAMs strongly interact with graphene allowing for a cleaner graphene transfer and enhanced charge mobility.