• 文献标题:   Determination of Work Function of Graphene under a Metal Electrode and Its Role in Contact Resistance
  • 文献类型:   Article
  • 作  者:   SONG SM, PARK JK, SUL OJ, CHO BJ
  • 作者关键词:   graphene, work function, contact resistance, capacitancevoltage, flat band voltage
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Korea Adv Inst Sci Technol
  • 被引频次:   159
  • DOI:   10.1021/nl300266p
  • 出版年:   2012

▎ 摘  要

Although the work function of graphene under a given metal electrode is critical information for the realization of high-performance graphene-based electronic devices, relatively little relevant research has been carried out to date. In this work, the work function values of graphene under various metals are accurately measured for the first time through a detailed analysis of the capacitance-voltage (C-V) characteristics of a metal-graphene-oxide-semiconductor (MGOS) capacitor structure. In contrast to the high work function of exposed graphene of 489-5.16 eV, the work function of graphene under a metal electrode varies depending on the metal species. With a Cr/Au or Ni contact, the work function of graphene is pinned to that of the contacted metal, whereas with a Pd or Au contact the work function assumes a value of similar to 4.62 eV regardless of the work function of the contact metal. A study of the gate voltage dependence on the contact resistance shows that the latter case provides lower contact resistance.