Nanoscale mobility mapping in semiconducting polymer films

A. Alekseev, A. Yedrissov, G. J. Hedley, Olzhas Ibraikulov , T. Heiser, I. D.W. Samuel, S. Kharintsev

Research output: Contribution to journalArticle

Abstract

Local electrical properties of thin films of the polymer PTB7 are studied by conductive atomic force microscopy (C-AFM). Non-uniform nanoscale current distribution in the neat PTB7 film is revealed and connected with the existence of ordered PTB7 crystallites. The shape of local I-V curves is explained by the presence of space charge limited current. We modify an existing semi-empirical model for estimation of the nanoscale hole mobility from our experimental C-AFM measurements. The procedure of nanoscale charge mobility estimation was described and applied to the PTB7 films. The calculated average C-AFM hole mobility is in good agreement with macroscopic values reported for this material. Mapping of nanoscale hole mobility was achieved using the described procedure. Local mobility values, influenced by nanoscale structure, vary more than two times in value and have a root-mean-square value 0.22 × 10−8 m2/(Vs), which is almost 20% from average hole mobility.

Original languageEnglish
Article number113081
JournalUltramicroscopy
Volume218
DOIs
Publication statusPublished - Nov 2020

Keywords

  • Charge carrier mobility
  • Conductive AFM
  • Current distribution
  • Organic semiconductor
  • Space charge limited current

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Instrumentation

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  • Cite this

    Alekseev, A., Yedrissov, A., Hedley, G. J., Ibraikulov , O., Heiser, T., Samuel, I. D. W., & Kharintsev, S. (2020). Nanoscale mobility mapping in semiconducting polymer films. Ultramicroscopy, 218, [113081]. https://doi.org/10.1016/j.ultramic.2020.113081