高效厚膜型全聚合物太阳电池给体材料的设计与性能研究

All-polymer solar cells (all-PSCs) have attracted considerable attention in the past few years, because of their outstanding photochemical, thermal, and mechanical stabilities. Compared with traditional fullerene acceptors, the π electron orbitals of polymer acceptor molecules have anisotropic characteristics. Therefore, we need to design the molecular structure of the donor materials to prepare thick film all-PSCs with high efficiency. The thick film all-PSCs is very important for application in future fabrication of large area devices. In this project, we will design and develop a series of novel polymer donor materials with large π-fused ring structures for the unique optoelectronic and aggregation properties of polymer acceptor. The properties of optical absorption, energy level, carrier transport are controlled by conjugated units, symmetric/asymmetrical alkyl substituents, substituted sulfur/oxygen atom, and regularity, etc. The internal relationship between the morphology of active layer, molecular structure and device fabrication will be investigated. The influencing factors and mechanisms of performance for the thick film all-PSCs will be explored. The implementation of this project will provide a new research idea for designing thick-film all-PSCs with high efficiency, and promote organic solar cells from the laboratory to commercial applications.

全聚合物太阳电池（all-PSCs）具有优异的光/热稳定性和机械性能等特色优势，成为近几年有机光伏领域的研究热点。由于聚合物受体与富勒烯受体不同，其π电子轨道具有各向异性的特征，需要对给体材料的分子结构进行针对性设计，才能提高厚膜型all-PSCs的效率，对将来制备大面积柔性光伏器件具有重要意义。本项目拟针对聚合物受体的独特光电性质及聚集特性，以苯并噻唑结构为基础，通过控制并环条件，简单有效的设计一系列带隙不同、平面性更好的新型稠环结构及聚合物给体，通过共轭骨架、对称/不对称侧链基团、硫/氧原子取代、规整度等方式调控其光学吸收、能级结构、载流子传输等性质，研究不同厚度活性层的微观形貌与给/受体材料的分子结构、器件工艺的内在联系，探索影响厚膜型all-PSCs器件性能的因素及影响机制。本项目的实施将提供一种新的高效厚膜型all-PSCs设计研究思路，推动有机太阳电池的商业化应用。

本项目拟针对聚合物受体材料独特的光电性质及聚集特性，以苯并噻唑结构为基础单元，设计合成制备一系列光学带隙不同的新型D-A型共轭聚合物给体材料。通过共轭骨架、杂原子取代、侧链基团等方式调控其光学吸收、能级结构、载流子传输等性质，研究活性层的微观形貌与给/受体材料的分子结构、器件工艺的内在联系，探索影响器件性能的因素及影响机制。.围绕这些研究目标，本项目开展以下研究内容，并取得以下成果：通过制备基于苯并噻二唑并喹喔啉单元的新型近红外共轭聚合物材料体系，系统研究了侧链结构对材料器件性能的影响机制；通过制备基于苯并噻唑单元的宽带隙共轭聚合物，研究杂原子取代、分子量等对活性层微观形貌、器件性能的作用机制，获得了超过12%的光电转换效率；研究宽带隙材料化学能级时，发现其带隙适合光解水制氢，将亲水性二苯并噻吩砜单元以及寡聚乙二醇侧链单元引入其中进行改性，制备合成了多个体系的新型共轭多孔聚合物材料体系，系统研究其光物理性质、热稳定性、电化学性质及电荷传输性质，结合光电转化性能，深入分析、理解相关性质的作用机制。