Influence of Defects on the Schottky Barrier Height at BaTiO3/RuO2 Interfaces

Katharina N.S. Schuldt; Hui Ding; Jean Christophe Jaud; Jurij Koruza; Andreas Klein

doi:10.1002/pssa.202100143

Influence of Defects on the Schottky Barrier Height at BaTiO₃/RuO₂ Interfaces

Katharina N.S. Schuldt, Hui Ding, Jean Christophe Jaud, Jurij Koruza, Andreas Klein^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

The Schottky barrier formation between polycrystalline acceptor-doped BaTiO₃ and high work function RuO₂ is studied using photoelectron spectroscopy. Schottky barrier heights for electrons of ≈1.4 eV are determined, independent of doping level and oxygen vacancy concentration of the substrates. The insensitivity of the barrier height is related to the high permittivity of BaTiO₃, which results in space-charge regions (SCRs) being considerably wider than the inelastic mean free path of the photoelectrons. SCRs at any kind of interface should, therefore, be more important for the electronic and ionic conductivities in BaTiO₃ than in materials with lower permittivity. A Ba-rich phase at the surface of reduced acceptor-doped BaTiO₃ is also identified, which is explained by the formation of Ti vacancies in the 2D electron gas region at the surface.

Original language	English
Article number	2100143
Journal	Physica Status Solidi (A) Applications and Materials Science
Volume	218
Issue number	14
DOIs	https://doi.org/10.1002/pssa.202100143
Publication status	Published - Jul 2021
Externally published	Yes

Keywords

BaTiO
defects
Schottky barriers

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Surfaces and Interfaces
Surfaces, Coatings and Films
Electrical and Electronic Engineering
Materials Chemistry

Fields of Expertise

Advanced Materials Science

Access to Document

10.1002/pssa.202100143

Cite this

@article{46a4509611e84baeb174aa253a9a897d,

title = "Influence of Defects on the Schottky Barrier Height at BaTiO3/RuO2 Interfaces",

abstract = "The Schottky barrier formation between polycrystalline acceptor-doped BaTiO3 and high work function RuO2 is studied using photoelectron spectroscopy. Schottky barrier heights for electrons of ≈1.4 eV are determined, independent of doping level and oxygen vacancy concentration of the substrates. The insensitivity of the barrier height is related to the high permittivity of BaTiO3, which results in space-charge regions (SCRs) being considerably wider than the inelastic mean free path of the photoelectrons. SCRs at any kind of interface should, therefore, be more important for the electronic and ionic conductivities in BaTiO3 than in materials with lower permittivity. A Ba-rich phase at the surface of reduced acceptor-doped BaTiO3 is also identified, which is explained by the formation of Ti vacancies in the 2D electron gas region at the surface.",

keywords = "BaTiO, defects, Schottky barriers",

author = "Schuldt, {Katharina N.S.} and Hui Ding and Jaud, {Jean Christophe} and Jurij Koruza and Andreas Klein",

note = "Funding Information: This work was supported by the US Air Force of Scientific Research under contract number FA9550‐18‐1‐0385 and by the LOEWE program of the state of Hessen, Germany, within the project FLAME. They also appreciate discussion with Roger A. De Souza and Till Fr{\"o}mling. Publisher Copyright: {\textcopyright} 2021 The Authors. physica status solidi (a) applications and materials science published by Wiley-VCH GmbH",

year = "2021",

month = jul,

doi = "10.1002/pssa.202100143",

language = "English",

volume = "218",

journal = "Physica Status Solidi (A) Applications and Materials Science",

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publisher = "Wiley-VCH ",

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T1 - Influence of Defects on the Schottky Barrier Height at BaTiO3/RuO2 Interfaces

AU - Schuldt, Katharina N.S.

AU - Ding, Hui

AU - Jaud, Jean Christophe

AU - Koruza, Jurij

AU - Klein, Andreas

N1 - Funding Information: This work was supported by the US Air Force of Scientific Research under contract number FA9550‐18‐1‐0385 and by the LOEWE program of the state of Hessen, Germany, within the project FLAME. They also appreciate discussion with Roger A. De Souza and Till Frömling. Publisher Copyright: © 2021 The Authors. physica status solidi (a) applications and materials science published by Wiley-VCH GmbH

PY - 2021/7

Y1 - 2021/7

N2 - The Schottky barrier formation between polycrystalline acceptor-doped BaTiO3 and high work function RuO2 is studied using photoelectron spectroscopy. Schottky barrier heights for electrons of ≈1.4 eV are determined, independent of doping level and oxygen vacancy concentration of the substrates. The insensitivity of the barrier height is related to the high permittivity of BaTiO3, which results in space-charge regions (SCRs) being considerably wider than the inelastic mean free path of the photoelectrons. SCRs at any kind of interface should, therefore, be more important for the electronic and ionic conductivities in BaTiO3 than in materials with lower permittivity. A Ba-rich phase at the surface of reduced acceptor-doped BaTiO3 is also identified, which is explained by the formation of Ti vacancies in the 2D electron gas region at the surface.

AB - The Schottky barrier formation between polycrystalline acceptor-doped BaTiO3 and high work function RuO2 is studied using photoelectron spectroscopy. Schottky barrier heights for electrons of ≈1.4 eV are determined, independent of doping level and oxygen vacancy concentration of the substrates. The insensitivity of the barrier height is related to the high permittivity of BaTiO3, which results in space-charge regions (SCRs) being considerably wider than the inelastic mean free path of the photoelectrons. SCRs at any kind of interface should, therefore, be more important for the electronic and ionic conductivities in BaTiO3 than in materials with lower permittivity. A Ba-rich phase at the surface of reduced acceptor-doped BaTiO3 is also identified, which is explained by the formation of Ti vacancies in the 2D electron gas region at the surface.

KW - BaTiO

KW - defects

KW - Schottky barriers

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