title: Fulleropyrrolidine interlayers: tailoring electrodes to raise organic solar cell efficiency.
abstract: A major challenge in organic solar cell design is the trade-off between oxidative stability and work function of the metal cathode. We found that in single-junction polymer solar cells, this problem can be surmounted by solution-based incorporation of fulleropyrrolidines with amine (C60-N) or zwitterionic (C60-SB) substituents as cathode-independent buffer layers. Specifically, a thin layer of C60-N reduced the effective work function of Ag, Cu, and Au electrodes to 3.65 electron volts. Power conversion efficiency values exceeding 8.5% were obtained for organic photovoltaics independent of the cathode selection (Al, Ag, Cu, or Au). Such high efficiencies did not require precise control over interlayer thickness, as devices prepared with C60-N and C60-SB layers ranging from 5 to 55 nanometers performed with high efficiency.
authors.affiliation: Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Zachariah A
authors.initials: ZA
authors.lastname: Page
authors.affiliation: Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA. tsemrick@mail.pse.umass.edu russell@mail.pse.umass.edu duzhko@mail.pse.umass.edu.
authors.forename: Volodimyr V
authors.initials: VV
authors.lastname: Duzhko
authors.affiliation: Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA. tsemrick@mail.pse.umass.edu russell@mail.pse.umass.edu duzhko@mail.pse.umass.edu.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Russell
authors.affiliation: Polymer Science and Engineering Department, University of Massachusetts, Amherst, MA 01003, USA. tsemrick@mail.pse.umass.edu russell@mail.pse.umass.edu duzhko@mail.pse.umass.edu.
authors.forename: Todd
authors.initials: T
authors.lastname: Emrick