Filling factor, conjugated polymers

Recently, photovoltaic cells that use a narrow band conjugated polymer PDDTT 196 as the electron donor and fullerene derivative 197 as the electron acceptor were developed. These cells show a short circuit density (J c) of 0.83mAcm , an open current voltage (Fqc) of 0.35 V, a fill factor (FF) of 38.6% under AM.5 simulator (lOOmWcm ) and unprecedented photocurrent response wavelengths up to llOOnm <2006APY081106>. 

The fill factor (FF), defined as Ima.xVma.x/IScVoc, is 0.25. The relatively low FF may be explained by recombination of charges at the ITO electrode. The present values of Isc and Voc are significantly enhanced in comparison with the device characteristics of a related Ceo-oligophenylenevinylene dyad [102] and quite similar to those previously reported for 7r-conjugated polymer/fullerene solar cells [115], although there has been considerable progress in energy conversion efficiencies of these devices recently [116]. 

Keywords Solar cells, organic photovoltaics (OPVs), quantum confinement effect (QCE), conjugated polymers, nanocomposites, blends, quantum dots (QDs), nanocrystals, nanorods, carbon nanotubes (CNTs), graphene, nanoparticles, alternating copolymers, block copolymers, exdton diffusion length, short-circuit current, open-circuit voltage, fill factor, photoconversion efficiency, in-situ polymerization... 

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