Unusual resistance hysteresis in n-layer graphene field effect transistors fabricated on ferroelectric Pb(Zr0.2Ti0.8)O3

Authors

X. Hong, University of Nebraska–LincolnFollow
J. Hoffman, Yale University
A. Posadas, Yale University
K. Zou, The Pennsylvania State University
C. H. Ahn, Yale University
J. Zhu, The Pennsylvania State University

Date of this Version

2010

Document Type

Article

Citation

Appl. Phys. Lett. 97, 033114

Comments

Used by permission.

Abstract

We have fabricated n-layer graphene field effect transistors on epitaxial ferroelectric Pb(Zr_0.2Ti_0.8)O₃ (PZT) thin films. At low gate voltages, PZT behaves as a high-k dielectric with k up to 100. An unusual resistance hysteresis occurs in gate sweeps at high voltages, with its direction opposite to that expected from the polarization switching of PZT. The relaxation of the metastable state is thermally activated, with an activation barrier of 50–110 meV and a time constant of 6 h at 300 K. We attribute its origin to the slow dissociation/recombination dynamics of water molecules adsorbed at the graphene-PZT interface. This robust hysteresis can potentially be used to construct graphene-ferroelectric hybrid memory devices.