北京化工大学Zhi-Guo Zhang研究小组在太阳能电池研究中取得进展。他们通过芳烃核工程化的系链三聚体小分子受体制备了高效热稳定聚合物太阳能电池。这一研究成果于2024年2月6日发表在国际顶尖学术期刊《德国应用化学》上。

在这项研究中，课题组研究人员在二聚体的苯羧酸核心上启动了异构体工程，并通过在BDY-β的芳香核心上引入额外的小分子受体(SMA)单元来扩展他们的方法。这种系统的芳烃核心工程得到了星形C_3h定位的分子几何结构。与二聚体相比三聚体中SMA单元的超分子相互作用有助于提高Tg值、结晶度和红移吸收。这些特征导致能量转化效率显著增加至18.24%。更重要的是，基于三聚体的器件提供了出色的热稳定性。他们的发现强调了三聚体结构在实现高有序聚集行为，和提高Tg值以实现高效率和热稳定器件方面的前景和可行性。

研究人员表示，聚合物太阳能电池(PSCs)依赖于小分子受体(SMAs)和聚合物供体的混合物，其中小分子受体的热力学松弛对运行稳定性提出了关键问题。为了动态控制形貌并解决这一问题，研究人员提出了栓系小分子受体，其中小分子受体亚基通过柔性链连接到芳核，相对于单个小分子受体，可以提供更高的玻璃化转变温度(Tg)。然而，实现更高的功率转换效率(PCE)和更高的Tg值，对系固式小分子受体的设计提出了重大挑战。

附：英文原文

Title: Tethered Trimeric Small-molecular Acceptors through Aromatic-core engineering for Highly Efficient and Thermally Stable Polymer Solar Cells

Author: Bowen Chang, Yaogang Zhang, Cen Zhang, Ming Zhang, Qingyuan Wang, Zheng&#x, Qi Chen, Yang Bai, Hongyuan Fu, Shixin Meng, Lingwei Xue, Seoyoung Kim, Changduk Yang, Yuanping Yi, Zhi-Guo Zhang

Issue&Volume: 2024-02-06

Abstract: Polymer solar cells (PSCs) rely on a blend of small molecular acceptors (SMAs) with polymer donors, where thermodynamic relaxation of SMAs poses critical concerns on operational stability. In an effect to dynamically control morphology and tackle this issue, tethered SMAs, wherein SMA subunits are connected to the aromatic-core via flexible chains, are proposed to afford an elevated glass transition temperature (Tg) relative to individual SMAs. However, achieving both higher power conversion efficiency (PCE) and elevated Tg values presents a significant challenge for the design of tethered SMAs. In this study, we initiate isomer engineering on the benzene-carboxylate core on the dimers and expand our approach by introducing an additional SMA unit onto the aromatic core of BDY-β. This systematic aromatic-core engineering results in a star-shaped C3h-positioned molecular geometry. The supramolecular interactions of SMA units in the trimer contribute to enhancements in Tg value, crystallinity, and a red-shifted absorption compared to dimers. These characteristics result in a noteworthy increase in PCE to 18.24%. More significantly, the trimer-based devices delivered an excellent thermal stability. Our findings underscore the promise and feasibility of trimeric structures in achieving highly ordered aggregation behavior and increased Tg value for high efficiency and thermal stable device.

DOI: 10.1002/anie.202400590

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202400590