Determination of Work Function of Graphene under a Metal Electrode and Its Role in Contact Resistance

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 m...

Full description

Saved in:
Bibliographic Details
Published in:Nano letters 2012-08, Vol.12 (8), p.3887-3892
Main Authors: Song, Seung Min, Park, Jong Kyung, Sul, One Jae, Cho, Byung Jin
Format: Article
Language:English
Subjects:
Condensed matter: electronic structure, electrical, magnetic, and optical properties
Contact
Contact resistance
Cross-disciplinary physics: materials science
rheology
Electric potential
Electrodes
Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures
Exact sciences and technology
Fullerenes and related materials
diamonds, graphite
Gold
Graphene
Magnesium oxide
Materials science
Physics
Specific materials
Surface double layers, schottky barriers, and work functions
Voltage
Work functions
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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 4.89–5.16 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 ∼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.
ISSN:1530-6984
1530-6992
DOI:10.1021/nl300266p