基于萘并四噻吩单元的二维共轭高分子光伏给体材料

The two-dimensional conjugated polymer donor materials exhibited the significantly improved photovoltaic properties of polymer solar cells (PSC), indicating their high potential applications. However, the weak absorption in the short wavelength limited the further enhancing the device power conversion efficiency. In this project, we aim to develop two-dimensional conjugated polymer donor materials based on tetrathienonaphthalene (TTN) core, which owned the characteristic large and planar thiophene-fused polycyclic π framework. The conjugated side chains will be enlarged to broaden the absorption spectra, especially to enhance the absorption in the short-wavelength region. On the other hand, the planarity of the main and side chains could promote the molecular packing and enhance the hole mobility. This project will successfully develop the molecular design strategy of two-dimensional conjugated polymer donor materials, and provide some novel polymer donor materials for high-performance PSC.

高分子太阳能电池中的二维共轭高分子给体材料，器件效率高，具有光明的发展前景；但是其短波长区域吸光能力弱的特点，限制了器件效率的进一步提升。本项目旨在探索采用大π共轭噻吩稠环构建二维高分子给体材料，发展基于萘并四噻吩单元的二维共轭高分子给体材料。将利用萘并四噻吩单元大π共轭平面骨架的结构特点，一方面，增大高分子侧链的共轭体系，加强材料在较短波长范围的吸收；另一方面，使高分子侧链和主链更共平面化，促进主链在固态的紧密堆积，提高空穴传输能力。该研究将拓展二维共轭高分子给体材料分子设计的新方法，并开发出一类新型高分子给体材料，为实现高效高分子太阳能电池提供材料保障。

申请人以高分子太阳能电池为研究主题，发展二维共轭高分子给体材料和高分子电子受体材料为目标，开展了系列研究工作。发表学术论文13篇，包括Angew. Chem. Int. Ed. 3篇，Adv. Mater. 1篇, Chem. Sci. 1篇, Macromolecules 2篇等。申请中国发明专利4项，其中2项已获授权。主要成果有：（1）开发出含萘并四噻吩单元的二维共轭高分子，该类高分子具有高LUMO/HOMO能级和良好空穴迁移率，被用作高分子给体材料用于高分子太阳能电池；（2）提出采用硼氮配位键降低共轭高分子的LUMO/HOMO能级，发展高分子电子受体的思想。基于该思想，发展出两类含硼氮配位键高分子受体材料，都已实现了全高分子太阳能电池器件效率超过6%，为发展高分子受体提供了原创学术思想和全新材料体系。