高迁移率非富勒烯受体材料的设计、合成与光伏性能研究

For further improving the performance of organic solar cells (OSCs), it is crucial to enhance the electron mobility of non-fullerene acceptor materials. Thienoacenes have rigid and planar conjugated structures, which lead to low reorganization energy and benefit close pi-pi stacking. Therefore, in this project, we will introduce thienoacene units to non-fullerene acceptors to enhance intermolecular pi-pi overlap or intermolecular interaction. Two classes of conjugated molecules with strong electron-withdrawing 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile groups as terminus and indacenodithienoacenes and thienoacenes as center units, respectively, will be designed and synthesized. The condensed state structures of the molecules will be finely tuned by appropriately choosing side chains. The relationship between molecular structures, condensed state structures and electron mobility will be studied. Of these molecules, high electron mobility ones will be selected for OSCs fabrication. The film morphology with polymer donors will be optimized, and the correlation between device performance and active layer thickness will be explored. This study should be able to provide potential acceptor materials for preparing large area OSCs by printing techniques.

提高非富勒烯受体材料的电子迁移率对进一步提高有机太阳能电池（OSC）的性能具有重要意义。鉴于含噻吩并苯类芳香稠环化合物（thienoacenes）具有刚性平面的共轭结构，不仅重组能较低，而且利于分子间的紧密堆积，本项目提出将此类单元引入非富勒烯受体分子的构筑中，增大分子之间的pi-pi作用面积，增强分子间的相互作用，以具有强吸电子性的氰基茚酮为端基，设计并合成两类共轭分子，即以吲哒省并二thienoacene为中间单元和以thienoacenes为中间单元的共轭分子。通过优化侧链基团结构，进一步调控分子的聚集态结构，研究分子结构（包括稠环单元结构和侧链基团结构）-聚集态结构-电子迁移率之间的关系。筛选具有高迁移率特征的材料，调控其与聚合物给体材料共混薄膜的形貌，探索器件性能与活性层厚度的关系，为大面积印刷制备OSC提供材料基础。

具有高迁移率和良好吸光性质的有机半导体材料是制备高性能有机太阳能电池（OSC）的基础。本项目设计并合成了一系列含苯并二噻吩-4,8-二酮、硒吩及二噻吩并咔唑的非富勒烯受体分子，基本完成了项目的研究内容和研究目标。发表学术论文9篇，包括Joule 1篇、J. Mater. Chem. A 2篇。培养硕士研究生3名。主要研究结果有：. （1）引入苯并二噻吩-4,8-二酮为中间单元，利用分子内非共价相互作用，获得了具有良好平面性的非稠环型非富勒烯受体分子，该材料的电子迁移率达到7.0×10-4 cm2 V-1 s-1，OSC器件PCE超过10%。（2）以硒吩为π桥连接中间单元及末端基团，增强分子内的电荷转移及分子间的π-π相互作用，获得了具有近红外吸收且良好电荷传输性质的非富勒烯材料，并制备了PCE > 11 %的OSC器件效率。