We demonstrated the performance of unconventional, all-fullerene-based, planar heterojunction (PHJ) organic photovoltaic (OPV) cells using fullerene derivatives indene-C 60 bisadduct (ICBA) and phenyl C 61 -butyric acid methyl ester as the electron donors with fullerene C 70 as the electron acceptor. Two different charge generation processes, including charge generation in the fullerene bulk and exciton dissociation at the donor-acceptor interface, have been found to exist in such all-fullerene-based PHJ cells and the contribution to the total photocurrent from each process is strongly dependent on the thickness of fullerene donor. The optimized 5 nm ICBA/40 nm C 70 PHJ cell gives clear external quantum efficiency responses for the long-wavelength photons corresponding to the dissociation of strongly bound Frenkel excitons, which is hardly observed in fullerene-based single layer reference devices. This approach using fullerene as a donor material provides further possibilities for developing high performance OPV cells. V C 2013 AIP Publishing LLC. [http://dx.

In this study, we describe photosynthetic active layers-based photovoltaic cells employing a linear carotenoid as the donor and chlorophyll derivatives as the acceptors.

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In this study, we fabricated planar heterojunction photovoltaic cells with inverted device structures based on tetraphenyldibenzoperiflanthene and fullerene-70 (C70). With proper designs of device architecture and selection of electrode buffers, a high fill factor and power conversion efficiency were obtained due to large shunt resistance (Rsh) and efficient carrier collection. Optical simulation reveals that field-dependent recombination is depressed in the inverted structure cells because of less light absorption in short wavelength range, resulting in high fill factor. More importantly, high thermal stability of inverted structure cells was demonstrated via utilizing stable electrode buffers.

A π-extension strategy is an effective way for squaraines for achieving high-performance photovoltaic materials capable of showing much enhanced hole mobility.