Nano-porous Poly(3-hexylthiophene) films: A novel route to prepare bulk heterojunction photovoltaic devices

ORAL

Abstract

Conjugated polymers are excellent candidates for use in low-cost electronics and photovoltaics applications. Bulk heterojunction (BHJ) morphologies are promising device architecture as the close proximity of the electron donor and acceptor micro-domains (with domain size comparable with the exciton diffusion length) facilitates the charge transport process. In order to achieve a well ordered BHJ architecture, poly(3-hexylthiophene) (P3HT) based rod-coil copolymers are synthesized where coil blocks are grafted to the P3HT chain through a cleavable linker. The linker and the attached sacrificial coil block can easily be cleaved and removed by chemical treatment leaving a rough nano-porous P3HT film. Scanning force microscopy and grazing incidence small angle X-ray scattering convincingly show the nano-pore formation. Further, depth profiling using dynamic secondary ion mass spectroscopy indicates that nano-pores probably penetrate the entire depth of the film (device thickness). Subsequently refilling of the nano-pores by electron transporting component (fullerene derivatives) provides the required device morphology.

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Authors

  • Tirtha Chatterjee

    • Mitsubishi Chemicals-Center for Advanced Materials, Materials Research Laboratory, University of California, Santa Barbara, CA 93106
    • UC Santa Barbara

  • Kulandaivelu Sivanandan

    • Mitsubishi Chemicals-Center for Advanced Materials, Materials Research Laboratory, University of California, Santa Barbara, CA 93106

  • Craig J. Hawker

    • Mitsubishi Chemicals-Center for Advanced Materials, Materials Research Laboratory, University of California, Santa Barbara, CA 93106

  • Ed Kramer

    • UCSB - MC CAM
    • Department of Materials and Chemical Engineering, University of California Santa Barbara
    • University of California, Santa Barbara
    • Mitsubishi Chemicals-Center for Advanced Materials, Materials Research Laboratory, University of California, Santa Barbara, CA 93106
    • UCSB
    • Materials Research Laboratory, University of California, Santa Barbara
    • Materials Department, UCSB
    • University of California Santa Barbara