Effect of Carbon Chain Length in the Substituent of PCBM-like Molecules on Their Photovoltaic Properties

Authors

  • Guangjin Zhao,

    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    2. Graduate University of Chinese Academy of Sciences Beijing 100039 (P. R. China)
    Search for more papers by this author
  • Youjun He,

    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    2. Graduate University of Chinese Academy of Sciences Beijing 100039 (P. R. China)
    Search for more papers by this author
  • Zheng Xu,

    1. Solarmer Energy Inc. El Monte, California 91731 (USA)
    Search for more papers by this author
  • Jianhui Hou,

    Corresponding author
    1. Solarmer Energy Inc. El Monte, California 91731 (USA)
    • Solarmer Energy Inc. El Monte, California 91731 (USA)
    Search for more papers by this author
  • Maojie Zhang,

    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    2. Graduate University of Chinese Academy of Sciences Beijing 100039 (P. R. China)
    Search for more papers by this author
  • Jie Min,

    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    Search for more papers by this author
  • Hsiang-Yu Chen,

    1. Department of Materials Science and Engineering & California Nanosystems Institute University of California at Los Angeles Los Angeles, California 90095 (USA)
    Search for more papers by this author
  • Mingfu Ye,

    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    2. Graduate University of Chinese Academy of Sciences Beijing 100039 (P. R. China)
    Search for more papers by this author
  • Ziruo Hong,

    1. Department of Materials Science and Engineering & California Nanosystems Institute University of California at Los Angeles Los Angeles, California 90095 (USA)
    Search for more papers by this author
  • Yang Yang,

    Corresponding author
    1. Department of Materials Science and Engineering & California Nanosystems Institute University of California at Los Angeles Los Angeles, California 90095 (USA)
    • Department of Materials Science and Engineering & California Nanosystems Institute University of California at Los Angeles Los Angeles, California 90095 (USA)
    Search for more papers by this author
  • Yongfang Li

    Corresponding author
    1. Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    • Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 (P. R. China)
    Search for more papers by this author

Abstract

A series of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)-like fullerene derivatives with the butyl chain in PCBM changing from 3 to 7 carbon atoms, respectively (F1–F5), are designed and synthesized to investigate the relationship between photovoltaic properties and the molecular structure of fullerene derivative acceptors. F2 with a butyl chain is PCBM itself for comparison. Electrochemical, optical, electron mobility, morphology, and photovoltaic properties of the molecules are characterized, and the effect of the alkyl chain length on their properties is investigated. Although there is little difference in the absorption spectra and LUMO energy levels of F1–F5, an interesting effect of the alkyl chain length on the photovoltaic properties is observed. For the polymer solar cells (PSCs) based on P3HT as donor and F1–F5, respectively, as acceptors, the photovoltaic behavior of the P3HT/F1 and P3HT/F4 systems are similar to or a little better than that of the P3HT/PCBM device with power conversion efficiencies (PCEs) above 3.5%, while the performances of P3HT/F3 and P3HT/F5-based solar cells are poorer, with PCE values below 3.0%. The phenomenon is explained by the effect of the alkyl chain length on the absorption spectra, fluorescence quenching degree, electron mobility, and morphology of the P3HT/F1–F5 (1:1, w/w) blend films.

Ancillary