Suppressing Subnanosecond Bimolecular Charge Recombination in a High-Performance Organic Photovoltaic Material

Abstract

Nanoscale morphology and spin can have a significant impact on charge generation and short time scale recombination in organic photovoltaic materials. We reveal multiple efficient charge separation pathways and the suppression of triplet loss channels in a high-performing nematic liquid crystalline electron donor, benzodithiophene terthiophene rhodanine (BTR). BTR:PC71BM bulk heterojunction photovoltaic devices have been shown to exhibit charge generation quantum yields of ∼90% and power conversion efficiencies >9.5%, even in thick devices. Solvent vapor annealing increases device efficiency, delivering performance almost twice as high as that of untreated blend films, despite reduced excito..