Qun Wan1, Xia Guo1,*（国霞）, Zaiyu Wang2, Wanbin Li1, Bing Guo1,Wei Ma（马伟）2,*, Maojie Zhang1,*（张茂杰）,Yongfang Li1
1Laboratory of Advanced Optoelectronic Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, P. R. China
2State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, P. R. China
Adv. Funct. Mater. 2016, 26, 6635–6640
In this work, polymer solar cells are fabricated based on the blend of PTB7-Th: PC71BM by using a mixed solvent additive of 1,8-diiodooctane and N-methyl pyrrolidone to optimize the morphology of the blend. A high power conversion efficiency (PCE) of 10.8% has been achieved with a simple conventional device. In order to deeply investigate the influence of the mixed solvent additives on the morphology and device performance, the variations of the molecular packing and bulk morphology of the blend film cast from ortho-dichlorobenzene with single or binary solvent additives are measured. Although all the blend films exhibit similar domain size and nanoscale phase separation, the blend film processed with mixed solvent additive shows the highest domain purity, resulting in the least bimolecular recombination, relatively high Jsc and FF, and hence enhanced PCE. Therefore, the best photovoltaic performance with the Voc of 0.82 V, Jsc of 19.1 mA cm−2, FF of 69.1%, and PCE of 10.8% are obtained for the device based on the blend with binary solvent additive treatment.
链接：http://onlinelibrary.wiley.com/doi/10.1002/adfm.201602181/abstract