Out-of-plane interface dipoles and anti-hysteresis in graphene-strontium titanate hybrid transistor

Sahoo, A and Nafday, D and Paul, T and Ruiter, R and Roy, A and Mostovoy, M and Banerjee, T and Saha-Dasgupta, T and Ghosh, A (2018) Out-of-plane interface dipoles and anti-hysteresis in graphene-strontium titanate hybrid transistor. In: npj 2D Materials and Applications, 2 (1).

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Abstract

The out-of-plane electric polarization at the surface of SrTiO3 (STO), an archetypal perovskite oxide, may stabilize new electronic states and/or host novel device functionality. This is particularly significant in proximity to atomically thin membranes, such as graphene, although a quantitative understanding of the polarization across graphene–STO interface remains experimentally elusive. Here, we report direct observation and measurement of a large intrinsic out-of-plane polarization at the interface of single-layer graphene and TiO2-terminated STO (100) crystal. Using a unique temperature dependence of anti-hysteretic gate-transfer characteristics in dual-gated graphene-on-STO field-effect transistors, we estimate the polarization to be as large as ≈12 μC cm−2, which is also supported by the density functional theory calculations and low-frequency noise measurements. The anti-hysteretic transfer characteristics is quantitatively shown to arise from an interplay of band bending at the STO surface and electrostatic potential due to interface polarization, which may be a generic feature in hybrid electronic devices from two-dimensional materials and perovskite oxides.

Item Type:	Journal Article
Publication:	npj 2D Materials and Applications
Publisher:	Nature Publishing Group
Additional Information:	The copyright for this article belongs to the Authors.
Keywords:	Density functional theory; Electrostatic devices; Field effect transistors; Graphene; Hybrid materials; Hysteresis; Perovskite; Polarization; Strontium titanates; Temperature distribution; Titanium dioxide, Direct observations; Electric polarization; Electrostatic potentials; Low-frequency noise measurements; Perovskite oxides; Temperature dependence; Transfer characteristics; Two-dimensional materials, Graphene transistors
Department/Centre:	Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Physics
Date Deposited:	03 Aug 2022 11:56
Last Modified:	03 Aug 2022 11:56
URI:	https://eprints.iisc.ac.in/id/eprint/75277

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