Improved Performance of Perylene-Based Photovoltaic Cells Using Polyisocyanopeptide Arrays

Photovoltaic devices incorporating perylene-substituted polyisocyanide materials have been demonstrated, using blend systems with polythiophene- and polyfluorene-based conjugated polymers. Prototypical structures with nominal (1:1) blend weight ratios of the polyisocyanide with poly(3-hexylthiophene) (P3HT) and poly(9,9′-dioctylfluorene-co-bis(N,N′-(4-butylphenyl))-bis(N,N′-phenyl)-1,4-phenyldiamine) (PFB) readily showed an order of magnitude improvement in power conversion efficiency, as compared to analogous blend architectures using a perylene (PDI) monomer, whereas the performance of strongly phase-separated F8BT (poly(9,9-dioctylfluorene-co-benzothidiazole) blend devices showed no such improvement. We propose that the use of polyisocyanide chains as a molecular template offers a method by which the morphology and connectivity of photovoltaic blends can be modified and enhanced.