Remote surface optical phonon scattering in ferroelectric Ba_0.6Sr_0.4TiO₃ gated graphene

Authors

Hanying Chen, University of Nebraska-LincolnFollow
Tianlin Li, University of Nebraska-LincolnFollow
Yifei Hao, University of Nebraska-Lincoln
Anil Rajapitamahuni, University of Nebraska - LincolnFollow
Zhiyong Xiao, University of Nebraska - LincolnFollow
Stefan Schoeche, University of Nebraska - Lincoln
Mathias Schubert, University of Nebraska-LincolnFollow
Xia Hong, University of Nebraska-LincolnFollow

ORCID IDs

Tianlin Li http://orcid.org/0000-0001-6408-642X

Yifei Hao http://orcid.org/0000-0002-8407-0377

Zhiyong Xiao http://orcid.org/0000-0003-2461-2338

Mathias Schubert http://orcid.org/0000-0001-6238-663X

Xia Hong http://orcid.org/0000-0002-7873-5774

Date of this Version

10-17-2022

Document Type

Article

Citation

J. Appl. Phys. 132, 154301 (2022); doi: 10.1063/5.0106939

Comments

Published by AIP Publishing. Used by permission.

Abstract

We report the effect of remote surface optical (RSO) phonon scattering on carrier mobility in monolayer graphene gated by ferroelectric oxide. We fabricate monolayer graphene transistors back-gated by epitaxial (001) Ba0.6Sr0.4TiO3 films, with field effect mobility up to 23,000 cm² V⁻¹ s⁻¹ achieved. Switching ferroelectric polarization induces nonvolatile modulation of resistance and quantum Hall effect in graphene at low temperatures. Ellipsometry spectroscopy studies reveal four pairs of optical phonon modes in Ba_0.6Sr_0.4TiO₃, from which we extract RSO phonon frequencies. The temperature dependence of resistivity in graphene can be well accounted for by considering the scattering from the intrinsic longitudinal acoustic phonon and the RSO phonon, with the latter dominated by the mode at 35.8 meV. Our study reveals the room temperature mobility limit of ferroelectric-gated graphene transistors imposed by RSO phonon scattering.