A determination of the Schottky barrier height at the interface between ferroelectric Pb(Zr,Ti)O 3
thin films and Pt by photoelectron spectroscopy is presented. Stepwise Pt deposition was performed
in situ onto a contamination-free Pb(Zr,Ti)O 3 thin film surface. The substrate surface is reduced
in the course of Pt deposition as evident from the observation of metallic Pb. The Fermi level is
found at E F ? E VB = 1.6 ? 0.1?eV above the valence band maximum of the as-prepared interface.
Annealing of the sample in an oxygen pressure of 0.1 and 1?Pa strongly reduces the amount of
metallic Pb and leads to a reduction in the Fermi level position at the interface to E F ? E VB =
1.1 ? 0.1?eV. Storage in vacuum at room temperature strongly reduces the interface leading to a
significantly higher Fermi level position ( E F ? E VB = 2.2 ? 0.1?eV). The reduction is attributed
to the presence of hydrogen in the residual gas. The change in barrier height might be a severe
issue for stable device operation with Pt contacts even at ambient temperatures.
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