Morphology Control Effects of Ternary Blended ICBA Toward Low-Temperature-Processed Thick-Film Organic Solar Cells

Abstract

We obtain an improvement of the power conversion efficiency of organic solar cell (OSC) from 8.06% to 9.81% by blending indene-C60 bis-adduct (ICBA) in the poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3′′′-di(2-octyl-dodecyl) -2,2′;5′,2′′;5′′,2′′′-quaterthiophen-5, 5′′′-diyl)]: [6,6]-phe-nyl C71-butyric acid methyl ester (PffBT4T-2OD: PCBM) active layer. We find the incorporation of ICBA could lead to the PffBT4T-2OD: PCBM solution with less temperature-dependent preaggregation, thus promoting the crystalline and preferable morphology of the active layer. Additionally, we demonstrate the addition of ICBA can increase the charge carrier lifetime, ensuring efficient charge carrier transport and collection with suppressed bimolecular recombination and thus enhanced FF. This paper illustrates a valuable strategy toward low-temperature-processed thick-film OSCs with high performances.