TY - JOUR
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
UR - http://www.scopus.com/inward/record.url?scp=85107328779&partnerID=8YFLogxK
U2 - 10.1002/pssa.202100143
DO - 10.1002/pssa.202100143
M3 - Article
AN - SCOPUS:85107328779
SN - 1862-6300
VL - 218
JO - Physica Status Solidi (A) Applications and Materials Science
JF - Physica Status Solidi (A) Applications and Materials Science
IS - 14
M1 - 2100143
ER -