Jump to main content
Jump to site search

Issue 40, 2012
Previous Article Next Article

Revisiting electronic couplings and incoherent hopping models for electron transport in crystalline C60 at ambient temperatures

Author affiliations

Abstract

We assess the validity of incoherent hopping models that have previously been used to describe electron transport in crystalline C60 at room temperature. To this end we present new density functional theory based calculations of the electron transfer parameter defining these models. Specifically, we report electronic coupling matrix elements for several ten thousand configurations that are thermally accessible to the C60 molecules through rotational diffusion around their lattice sites. We find that the root-mean-square fluctuations of the electronic coupling matrix element (11 meV) are almost as large as the average value (14 meV) and that the distribution is well approximated by a Gaussian. Importantly, due to the small reorganisation energy of the C60 dimer (≈0.1 eV), the ET is almost activationless for the majority of configurations. Yet, for a small but significant fraction of orientations the coupling is so strong compared to reorganisation energy that no charge-localised state exists, a situation that is aggravated if zero-point motion of the nuclei is taken into account. The present calculations indicate that standard hopping models do not provide a sound description of electron transport in C60, which might be the case for many other organics as well, and that approaches are needed that solve the electron dynamics directly.

Graphical abstract: Revisiting electronic couplings and incoherent hopping models for electron transport in crystalline C60 at ambient temperatures

Back to tab navigation

Publication details

The article was received on 27 Apr 2012, accepted on 17 Jul 2012 and first published on 18 Jul 2012


Article type: Paper
DOI: 10.1039/C2CP41348E
Citation: Phys. Chem. Chem. Phys., 2012,14, 13846-13852
  •   Request permissions

    Revisiting electronic couplings and incoherent hopping models for electron transport in crystalline C60 at ambient temperatures

    H. Oberhofer and J. Blumberger, Phys. Chem. Chem. Phys., 2012, 14, 13846
    DOI: 10.1039/C2CP41348E

Search articles by author

Spotlight

Advertisements