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Changes in Schottky Barrier Height Behavior of Pt–Ru Alloy Contacts on Single-Crystal ZnO

  • Takahiro NagataEmail author
Chapter
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Part of the NIMS Monographs book series (NIMSM)

Abstract

In this chapter, the Schottky contact formation and changes in Schottky barrier height (SBH) behavior of binary alloy contacts on n-type zinc oxide (n-ZnO) single crystals are shown. Pt–Ru alloy electrodes were deposited on the Zn-polar and O-polar faces of ZnO substrates by combinatorial ion-beam deposition under identical conditions. The crystal structures of the Pt–Ru alloy film changed from the Pt phase (cubic structure) to the Ru phase (hexagonal structure) in the Pt–Ru alloy phase diagram with decreasing Pt content. The SBH, determined from current–voltage measurements, decreased with decreasing Pt content, indicating that the SBH behavior also followed the Pt–Ru alloy phase diagram. The alloy electrodes on the Zn-polar face showed better Schottky properties than those on the O-polar face. Hard X-ray photoelectron spectroscopy revealed a difference in the interface oxidization of the Pt–Ru alloy: the interface of the O-polar face and Pt–Ru mixed phase with poor crystallinity had a more oxidized layer than that of the Zn-polar face. As a result of this oxidization, the O-polar face, Pt–Ru mixed phase, and Ru phase showed poor Schottky properties.

Keywords

Schottky contact Photoelectron spectroscopy Metal/oxide interface 

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Copyright information

© National Institute for Materials Science, Japan 2020

Authors and Affiliations

  1. 1.Research Center for Functional MaterialsNational Institute for Materials ScienceTsukubaJapan

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