Fluctuation-induced tunneling conductivity in nanoporous TiO2 thin films

Steven J. Konezny, Christiaan Richter, Robert C. Snoeberger, Alexander R. Parent, Gary W. Brudvig, Charles A. Schmuttenmaer, Victor S. Batista

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Abstract

The electronic mechanisms responsible for dark conductivity in nanoporous TiO2 thin films remain only partially understood, although they control the efficiency of charge transport in a wide range of technological applications. Measurements in the 78-335 K temperature range show DC conductivity values spanning over 4 orders of magnitude, with a high-temperature Arrhenius dependence that gradually changes into a temperature-independent plateau at low temperatures. We show evidence that a fluctuation-induced tunneling conductivity (FITC) mechanism is fully consistent with the experimental data. Quantitative agreement is demonstrated for the entire temperature range (T = 78-335 K) with a FITC model parametrized according to atomistic models of nanoporous TiO2 and the characterization of the films by X-ray diffraction and scanning electron microscopy measurements. These findings suggest that dark DC conductivity in nanoporous TiO2 films depends strongly on the properties of the junctions linking the constituent nanoparticles.

Original languageEnglish
Pages (from-to)1931-1936
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume2
Issue number15
DOIs
Publication statusPublished - Aug 4 2011

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Keywords

  • Electron Transport
  • Hard Matter
  • Optical and Electronic Devices

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Cite this

Konezny, S. J., Richter, C., Snoeberger, R. C., Parent, A. R., Brudvig, G. W., Schmuttenmaer, C. A., & Batista, V. S. (2011). Fluctuation-induced tunneling conductivity in nanoporous TiO2 thin films. Journal of Physical Chemistry Letters, 2(15), 1931-1936. https://doi.org/10.1021/jz200853v