Interface polarization coupling in piezoelectric-semiconductor ferroelectric heterostructures

Venkata M. Voora, T. Hofmann, M. Brandt, M. Lorenz, M. Grundmann, N. Ashkenov, H. Schmidt, N. Ianno, M. Schubert

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

We present a dielectric continuum model approach for studying the electrical polarization properties of interface polarization coupled BaTiO 3, BaTiO3 -ZnO, and ZnO-BaTiO3 -ZnO thin-film structures consisting of several hundred nanometer thick layers. Our model augments the effects of electric field driven switchable polarization and depletion layer formation with spontaneous interface polarization coupling. Wurtzite-structure (piezoelectric) n -type ZnO and perovskite-structure (ferroelectric) highly insulating BaTiO3 layers were prepared and investigated. The coupling between the nonswitchable spontaneous polarization of ZnO and the electrically switchable spontaneous polarization of BaTiO 3 causes strong asymmetric polarization hysteresis behavior. The n -type ZnO reveals hysteresis-dependent capacitance variations upon formation of depletion layers at the ZnO/BTO interfaces. We obtain a very good agreement between our model generated data and our experiment. Our model approach allows for derivation of the amount and orientation of the spontaneous polarization of the piezoelectric constituents and can be generalized toward multiple-layer piezoelectric-semiconductor ferroelectric heterostructures. We identify interface polarization coupled triple-layer ZnO-BTO-ZnO heterostructures as two-terminal unipolar ferroelectric Bi-junction transistor for use in memory storage.

Original languageEnglish (US)
Article number195307
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume81
Issue number19
DOIs
StatePublished - May 5 2010

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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