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Title: Switchable diode-effect mechanism in ferroelectric BiFeO{sub 3} thin film capacitors

We investigate the mechanism of a switchable diode behavior observed in ferroelectric SrRuO{sub 3}/BiFeO{sub 3} (BFO)/SrRuO{sub 3} capacitors. We experimentally demonstrate that the switchable diode effect observed in the capacitors is induced by the polarization reversal in the BFO film. The conductivity in an Ohmic region in different oxidation states provides direct evidence that electron hole acts as the majority carrier, delivering p-type conduction. Density functional theory (DFT) calculations show that the p-type conduction arises from an unoccupied gap state of Fe{sup 4+} in an FeO{sub 5} pyramid which is derived from Bi vacancy. Our experimental and DFT study leads to the conclusion that the switchable diode effect originates from an asymmetric band bending in the top and bottom depletion layers modulated by ferroelectric polarization and oxygen vacancies.
Authors:
 [1] ; ; ; ;  [2]
  1. Department of Advanced Interdisciplinary Studies, School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan)
  2. Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656 (Japan)
Publication Date:
OSTI Identifier:
22489493
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 11; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ASYMMETRY; CAPACITORS; CARRIERS; DEPLETION LAYER; FERROELECTRIC MATERIALS; HOLES; IRON IONS; IRON OXIDES; POLARIZATION; THIN FILMS; VACANCIES; VALENCE