Effect of Side Chain of Oligothiophene Derivatives on Bulk Heterojunction Structure in Organic Photovoltaic Devices


The effect of the molecular structure on photovoltaic performance was investigated by comparing two types of active layers. One is an active layer formed by sexithiophene (6T) and C60 molecules which don’t have side chains. Another one is an active layer formed by a,ω-bis(2-hexyldecyl)sexithiophene (BHD6T) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) molecules which have side chains. The 6T:C60 active layer exhibited an excessive crystallization of 6T, which led to the low photovoltaic performance. In the BHD6T:PCBM active layer, the crystallization of BHD6T was suppressed. The crystallization of BHD6T was also easily controlled by thermal annealing, which led to improved photovoltaic performance.

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K. Sasaki, Y. Shibata, M. Lu, Y. Yoshida, R. Azumi and Y. Ueda, "Effect of Side Chain of Oligothiophene Derivatives on Bulk Heterojunction Structure in Organic Photovoltaic Devices," Advances in Materials Physics and Chemistry, Vol. 3 No. 2, 2013, pp. 185-190. doi: 10.4236/ampc.2013.32026.

Conflicts of Interest

The authors declare no conflicts of interest.


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