Solar cells from thermally treated polymer/dye blends with good spectral coverage

We report a new photovoltaic material combination that comprises a blend of two conjugated polymers with a molecular dye. The constituents were chosen in order to achieve a wide spectral response. The polymer poly(9,9-bis(2-ethylhexyl)fluorene-2,7-diyl) (PF2/6) was blended with a polyphenylenevinylene derivative, Covion Super Yellow(TM) (SY), and violanthrone to produce a broad spectral response covering a large part of the visible spectrum. Annealing at 200degreesC in air leads to a roughly three-fold improvement in external quantum efficiency (EQE) and produces a structure with >1% EQE at all wavelengths between 350 and 650nm. (C) 2003 Elsevier B.V. All rights reserved.