We fabricated organic photovoltaic devices with
enhanced power conversion efficiency (PCE) upon using a
combination of two polymers with complementary
absorption spectra. The new ternary system is composed of
two electron-donor polymers, F8T2 and PTB7, and an
electron acceptor consisting of an organic soluble
fullerene, PC61BM. The results show that the photovoltage
is determined by PTB7, acting F8T2 as antenna that
increases the photon harvesting at higher energies and
therefore the charge generation efficiency. We
demonstrate PCE values as high as 7.0 % obtained under 1
sun AM 1.5G illumination which represents an
improvement in cells efficiency of 20 % comparing with
control devices based on binary systems