π-Conjugated molecular heterojunctions with multi[60]fullerene: photophysical, electrochemical, and photovoltaic properties

Abstract

A series of well-defined D–π-B–A C₆₀ adducts containing three chromophores and their corresponding precursors were facilely developed as organic photovoltaic materials. The photophysical and electrochemical properties indicated that effective photo-induced intramolecular and/or intermolecular energy transfer and charge transfer were formed from the donor chromophores to the C₆₀ moiety in thin films. Solution processed molecular heterojunction solar cells using 12 as active layer were fabricated with 2.0% monochromatic efficiency. Our results showed that further exploration might lead the way toward high-efficient solution-processed single molecular solar cell materials based on conjugated oligomer covalent to fullerene units.