Binary Additives Regulate the PCBM[70] Aggregate Morphology for
Highly Efficient Polymer Solar Cells

Abstract 

We optimized the performance of polymer solar cells (PSCs) based on PBDTTT-C-T:PC71BM

with the binary solvent additives of 1,8diiodomethane (DIO) and chloronaphthalene (CN). The

power conversion efficiency was significantly improvedfrom 3.44% for the PSC without additives

to 7.91% for the PSC with the additives (DIO/CN = 1:2). It is attributed to the achievement of highly

penetrating PC71BM aggregate structures, which have small aggregate particles, and dense and well-

packed pathways,inducing a high electron mobility. Our work not only provides an effective method

to regulate the PC71BM aggregate structures for highly efficient PSC devices but also indicates

an underlying mechanism of the performance enhancement by solvent additives.

Xi Fan* (樊细), Hao Wang(王浩)*, et al., ACS Photonics 2014,1,1278−1284.