Self-Assembling Tripodal Small-Molecule Donors for Bulk Heterojunction Solar Cells

Taner Aytun, Peter J. Santos, Carson J. Bruns, Dongxu Huang, Andrew R. Koltonow, Monica Olvera De La Cruz, Samuel I Stupp

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16 Citations (Scopus)

Abstract

The power conversion efficiency of organic solar cells (OSCs) could benefit from systematic studies to improve bulk heterojunction (BHJ) morphology by modifying donor compounds. Supramolecular self-assembly is an attractive strategy to combine the beneficial properties of polymeric donors, such as a well-controlled morphology, with the homogeneous composition of small molecule donors for OSCs. We report here on two tripodal "star-shaped" small-molecule donor compounds based on diketopyrrolopyrrole (DPP) side chains for solution-processed BHJ OSCs. The tripod molecules were found not to aggregate in solution or form crystalline domains in thin films when a branched alkyl chain (2-ethylhexyl) substituent was used, whereas linear (docedecyl) alkyl chains promote the formation of one-dimensional (1D) nanowires and more crystalline domains in the solid state. We demonstrate that the 1D self-assembly of these tripods enhances the performance of the corresponding solution-processed OSCs by 50%, which is attributed to the significant increase in the fill factor of devices resulting from a reduction of trap states.

Original languageEnglish
Pages (from-to)3602-3611
Number of pages10
JournalJournal of Physical Chemistry C
Volume120
Issue number7
DOIs
Publication statusPublished - Feb 25 2016

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials
  • Surfaces, Coatings and Films
  • Energy(all)

Cite this

Aytun, T., Santos, P. J., Bruns, C. J., Huang, D., Koltonow, A. R., Olvera De La Cruz, M., & Stupp, S. I. (2016). Self-Assembling Tripodal Small-Molecule Donors for Bulk Heterojunction Solar Cells. Journal of Physical Chemistry C, 120(7), 3602-3611. https://doi.org/10.1021/acs.jpcc.5b10064