The Influence of Driving Force on Formation and Geminate Recombination of Charges in Alternating Polyfluorene Copolymer/Fullerene Blends

Summary, in English

Conjugated polymer/fullerene-based solar cells are, due to their potential flexibility, cost efficiency and low weight, interesting as future alternatives to today’s silicon cells [1]. In these cells, both the dissociation of the polymer exciton into extractable charges, i.e. charges that are free and mobile, and the recombination of the free charges are expected to be crucial in order to obtain high light-to-charge conversion efficiencies. The exciton dissociation is believed to strongly depend upon the driving force [2] while the driving force dependence of the recombination has not been thoroughly investigated. Therefore, we have studied the charge formation and recombination in blends of alternating polyfluorene copolymers (APFO polymers) and PCBM with different driving force. By varying the polymer in the blends, a driving force range of 0.05–0.77 eV has been covered.