Highly Efficient All-Small-Molecule Organic Solar Cells with Appropriate Active Layer Morphology by Side Chain Engineering of Donor Molecules and Thermal Annealing
Highly Efficient All-Small-Molecule Organic Solar Cells with Appropriate Active Layer Morphology by Side Chain Engineering of Donor Molecules and Thermal Annealing
复制标题
通过供体分子的侧链工程和热退火制备具有适当活性层形态的高效全小分子有机太阳能电池
DOI：
10.1002/adma.201908373
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发表时间：
2020-05-01
影响因子：
29.4
通讯作者：
Li, Yongfang
中科院分区：
文献类型：
--
作者：
Qiu, Beibei;Chen, Zeng;Li, Yongfang
微调供体：受体共混活性层的纳米级形态对于提高全小分子有机太阳能电池（SM - OSCs）的光伏性能非常重要。在这项工作中，合成了两种在噻吩共轭侧链上具有不同取代基的新型小分子供体材料，包括带有烷硫基的SM1 - S和带有氟及烷基取代基的SM1 - F，以及先前报道的带有烷基取代基的供体分子SM1，以研究不同共轭侧链对供体分子的分子聚集、光物理和光伏性能的影响。结果表明，以Y6为受体、在120℃下热退火（TA）10分钟的基于SM1 - F的SM - OSC展现出14.07%的最高功率转换效率值，这是迄今为止报道的SM - OSCs的最佳值之一。此外，这些结果还表明，小分子的不同侧链能够显著影响结晶特性和聚集特征，并且热退火处理能够有效地微调相分离以形成合适的供体 - 受体互穿网络，这有利于激子解离和电荷传输，从而实现高效的光伏性能。
It is very important to fine-tune the nanoscale morphology of donor:acceptor blend active layers for improving the photovoltaic performance of all-small-molecule organic solar cells (SM-OSCs). In this work, two new small molecule donor materials are synthesized with different substituents on their thiophene conjugated side chains, including SM1-S with alkylthio and SM1-F with fluorine and alkyl substituents, and the previously reported donor molecule SM1 with an alkyl substituent, for investigating the effect of different conjugated side chains on the molecular aggregation and the photophysical, and photovoltaic properties of the donor molecules. As a result, an SM1-F-based SM-OSC with Y6 as the acceptor, and with thermal annealing (TA) at 120 degrees C for 10 min, demonstrates the highest power conversion efficiency value of 14.07%, which is one of the best values for SM-OSCs reported so far. Besides, these results also reveal that different side chains of the small molecules can distinctly influence the crystallinity characteristics and aggregation features, and TA treatment can effectively fine-tune the phase separation to form suitable donor-acceptor interpenetrating networks, which is beneficial for exciton dissociation and charge transportation, leading to highly efficient photovoltaic performance.