Materials for organic solar cells: the C60/π-conjugated oligomer approach

This tutorial review surveys recent advances in the field of C60/pi-conjugated oligomer donor-acceptor ensembles. In particular, different synthetic strategies are discussed that were developed to link pi-conjugated oligomers, as versatile photoexcited state electron donors, to C60. We highlight relationships between the nature/structural aspects of pi-conjugated donor systems and a variety of physico-chemical features. Modifications of the oligomeric components are discussed under aspects of tailoring (i) the absorption cross-section of the chromophore in the visible region, (ii) the oxidation potential of the oligomeric donor moiety, (iii) the size, shape, or chemical makeup of the oligomer, and (iv) the stabilization of the charge-separated radical ion pairs. In the final section, the applicability of selected materials for the fabrication of photovoltaic devices is analyzed.