Design, Synthesis and Properties of Low Band Gap Polyfluorenes for Photovoltaic Devices

Paper in proceeding, 2005

Two alternating polyfluorene-polythiophene copolymers contg. different low band gap 4,7-di-2-thienyl-2,1,3-benzothiadiazole-5,6-diamine segments were designed and synthesized for use in optoelectronic devices. The low band gap segments consist of electron donating and accepting moieties which induce a partial charge transfer in the polymer backbone and thereby, a lower band gap. The obtained polyfluorenes, APFO-Green1 and APFO-Green2, were studied by measuring optical absorption and emission at extended wavelengths. Blends of the polyfluorenes with fullerene derivs. exhibit unprecedented photovoltaic response at long wavelengths. [on SciFinder (R)]