New Acceptor Materials for Organic Photovoltaics: Design, Self-Assembly, Morphology and Photovoltaic Properties

Organic photovoltaics (OPVs) are of a great interest due to their potential as low cost solar energy conversion technologies.  Bulk heterojunction (BHJ) cells with an active layer consisting of a blend of a donor polymer and an acceptor material are among the most efficient OPV device architectures explored to date. In this talk, we present a series of 6 novel oligothiophene-naphthalene diimide-based oligomer semiconductors that were synthesized and used to evaluate factors essential to the design of non-fullerene acceptor materials for OPVs, including HOMO/LUMO energy levels offsets, optical absorption and band gap, charge transport and phase-separated morphology of the BHJ active layer film. We also demonstrate the first example of all nanowire organic solar cells and show that non-fullerene n-type organic semiconductor nanowires can be effectively incorporated into OPVs.