Optical anisotropy in single-walled carbon nanotube thin films: Implications for transparent and conducting electrodes in organic photovoltaics

Giovanni Fanchini, Steve Miller, Bhavin B. Parekh, Manish Chhowalla

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58 Citations (Scopus)

Abstract

Optical anisotropy in single-walled carbon nanotube thin film networks is reported. We obtain the real and imaginary parts of the in-(II) and out-of-plane (⊥) complex dielectric functions of the single-walled carbon nanotube (SWNT) thin films by combining transmission measurements at several incidence angles with spectroscopic ellipsometry data on different substrates. In sparse networks, the two components of the real part of the complex dielectric constant (ε and e 1⊥) were found to differ by 1.5 at 2.25 eV photon energy. The resulting angular dependence (from 0 to 70° incidence angles) of transmittance is reflected in the conversion efficiency of organic solar cells utilizing SWNT thin films as the hole conducting electrodes. Our results indicate that, in addition to the transparency and sheet resistance, factors such as the optical anisotropy must be considered for optical devices incorporating SWNT networks.

Original languageEnglish
Pages (from-to)2176-2179
Number of pages4
JournalNano letters
Volume8
Issue number8
DOIs
Publication statusPublished - Aug 1 2008

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ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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