The effect of intercalated behavior in polymer/fullerene blend on the performance of organic bulk heterojunction solar cells

Abstract

A review. The morphol. of active layer in organic bulk heterojunction solar cells had important influence on device performance. The intercalated behavior could exist when polymer/small mol. blend system met the two criteria: the size of the small mols. was smaller than the distance between adjacent side-chains of polymer, and the small mols. should form a ground-state charge-transfer complex with polymer. The intercalated behavior affected the film morphol. and was not beneficial to energy conversion process. In this paper, the forming process of intercalation in blend system was introduced. Then we concluded the influence of intercalation on film morphol. including crystallization, phase separation and device performance including exciton diffusion, exciton dissociation, and carrier transport. The chem. and phys. methods to inhibit intercalated behavior were also recommended at the same time. Furthermore, we posed the critical problems to be resolved in this field and prospect its developing foreground.