A Facile Method to Fine-Tune Polymer Aggregation Properties and Blend Morphology of Polymer Solar Cells Using Donor Polymers with Randomly Distributed Alkyl Chains

作者：Yao, Huatong; Li, Yunke; Hu, Huawei; Chow, Philip C. Y.; Chen, Shangshang; Zhao, Jingbo; Li, Zhengke; Carpenter, Joshua H.; Lai, Joshua Yuk Lin; Yang, Guofang; Liu, Yuhang; Lin, Haoran; Ade, Harald^*; Yan, He^*

来源：Advanced Energy Materials, 2018, 8(6): 1701895.

DOI：10.1002/aenm.201701895

• fullerene
• high efficiency
• polymer solar cells
• random polymers
• side-chain engineering

The device performance of polymer solar cells (PSCs) is strongly dependent on the blend morphology. One of the strategies for improving PSC performance is side-chain engineering, which plays an important role in controlling the aggregation properties of the polymers and thus the domain crystallinity/purity of the donor-acceptor blends. In particular, for a family of high-performance donor polymers with strong temperature-dependent aggregation properties, the device performances are very sensitive to the size of alkyl chains, and the best device performance can only be achieved with an optimized odd-numbered alkyl chain. However, the synthetic route of odd-numbered alkyl chains is costly and complicated, which makes it difficult for large-scale synthesis. Here, this study presents a facile method to optimize the aggregation properties and blend morphology by employing donor polymers with a mixture of two even-numbered, randomly distributed alkyl chains. In a model polymer system, this study suggests that the structural and electronic properties of the random polymers comprising a mixture of 2-octyldodecyl and 2-decyltetradecyl alkyl chains can be systematically tuned by varying the mixing ratio, and a high power conversion efficiency (11.1%) can be achieved. This approach promotes the scalability of donor polymers and thus facilitates the commercialization of PSCs.

• 出版日期2018-2-26
• 单位香港科技大学