Higher fullerenes as electron acceptors for polymer solar cells: A quantum chemical study

P. Morvillo

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31 Citations (Scopus)

Abstract

In the present study, we have used quantum chemical methods to study the energy levels of the frontier orbitals of higher fullerene derivatives (from C70to C84and having the same addend as in [6,6]-phenyl C61-butyric acid methyl ester) with the aim to understand if they can be used as electron acceptors in bulk heterojunction polymer-fullerene solar cells. Higher fullerenes have a stronger and broader absorption compared to C60and they can improve the current output of the corresponding devices. The geometries of all the compounds were optimized with the density functional theory at the B3LYP/3-21G* level of calculation. The lowest unoccupied molecular orbital (LUMO) levels of the investigated compounds correlate well with the reduction potentials (obtained by cyclic voltammetry) of the already prepared species. We found that the LUMO level depends not only on the fullerene size (number of carbons of the cage) and constitutional isomer, but also on the position and, in some cases, the addend orientation. This issue should be considered because for a proper device operation, a well-defined LUMO is required. The position of the LUMO level of some higher fullerene derivatives can be suitable for low-bandgap polymers. © 2009 Elsevier B.V. All rights reserved.
Original languageEnglish
Pages (from-to)1827 - 1832
Number of pages6
JournalSolar Energy Materials and Solar Cells
Volume93
Issue number10
DOIs
Publication statusPublished - Oct 2009
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films

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