Spin-Based Diagnostic of Nanostructure in Copper Phthalocyanine-C-60 Solar Cell Blends

Marc Warner, Soumaya Mauthoor, Solveig Felton, Wei Wu, Jules A. Gardener, Salahud Din, Daniel Klose, Gavin W. Morley, A. Marshall Stoneham, Andrew J. Fisher, Gabriel Aeppli, Christopher W. M. Kay, Sandrine Heutz

Research output: Contribution to journalArticle

24 Citations (Scopus)


Nanostructure and molecular orientation play a crucial role in determining the functionality of organic thin films. In practical devices, such as organic solar cells consisting of donor-acceptor mixtures, crystallinity is poor and these qualities cannot be readily determined by conventional diffraction techniques, while common microscopy only reveals surface morphology. Using a simple nondestructive technique, namely, continuous-wave electron paramagnetic resonance spectroscopy, which exploits the well-understood angular dependence of the g-factor and hyperfine tensors, we show that in the solar cell blend of C-60 and copper phthalocyanine (CuPc)-for which X-ray diffraction gives no information-the CuPc, and by implication the C-60, molecules form nanoclusters, with the planes of the CuPc molecules oriented perpendicular to the film surface. This information demonstrates that the current nanostructure in CuPc:C-60 solar cells is far from optimal and suggests that their efficiency could be considerably increased by alternative film growth algorithms.

Original languageEnglish
Pages (from-to)10808-10815
Number of pages8
JournalACS Nano
Issue number12
Publication statusPublished - 21 Dec 2012

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Warner, M., Mauthoor, S., Felton, S., Wu, W., Gardener, J. A., Din, S., Klose, D., Morley, G. W., Stoneham, A. M., Fisher, A. J., Aeppli, G., Kay, C. W. M., & Heutz, S. (2012). Spin-Based Diagnostic of Nanostructure in Copper Phthalocyanine-C-60 Solar Cell Blends. ACS Nano, 6(12), 10808-10815. https://doi.org/10.1021/nn304156e