Synthesis and characterization of pentacene- and anthradithiophene-fluorene conjugated copolymers synthesized by Suzuki reactions

We have synthesized new types of pentacene- and anthradithiophene-dialkylfluorene conjugated copolymer via Suzuki cross-coupling polymerization. The polymer chemical structures and molecular weights were characterized by H-1 NMR, C-13 NMR, and gel permeation chromatography (GPC). Fundamental properties, such as electrochemical and optical behavior, were studied using cyclic voltammetry (CV) and UV-vis absorption (UV-vis) to estimate the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels as well as their optical bandgaps. Both polymers exhibit relatively low bandgaps and their high solubility in common halogenated organic solvents. They were successfully incorporated into photovoltaic cells, giving a power efficiency up to 0.68%. This is the first acene-containing conjugated polymer solar cell.