吡咯并二噻吩稠环电子受体的分子工程及其高效率有机太阳能电池

Polymer solar cells (PSCs) using acceptor-donor-acceptor (A-D-A) structured nonfullerene acceptors (NFAs) have made great progress in recent years. The record power conversion efficiency (PCE) has overpassed 13% for binary solar cells and 14% for ternary ones. The further improvement in PCE for NFAs based PSCs strongly relies in the new design of fuse-ring acceptors. In this proposal, the applicant aims at realizing high-efficiency PSCs (PCE>14%) via the further structure optimization of our recent successfully developed dithienopyrrol fused-ring acceptors. The molecular engineering will be conducted from four levels, which include the conjugation extension and side-chain engineering of the central fused-ring donating block, screening and side-chain engineering of the terminal accepting units, and the introduction of extra conjugated blocks between D and A blocks for conformation locking of the resultant acceptors. The correlation study will be carried out between the structure modification of the dithienopyrrol fused-ring acceptors and the absorption, crystallization, molecular energy levels, bandgaps and solid-state packing behavior. On the basis of complementary absorption and matching energy levels, high-performance polymer donors will be screened for the preparation and optimization of binary solar cells. The effect of structure on both as-prepared new acceptors and polymer donors and their blend on the morphology in active layers and the photovoltaic properties of the devices will be investigated in details. In combination of device physics study, the mechanism for reducing energy loss in high-efficiency NFA PSCs will be revealed. The as-optimized acceptors will be explored in ternary solar cells and parallel tandem solar cells, aiming to realizing PCEs over 14% in these devices. Through this project, it is expected that the key factors affecting the performance of NFAs PSCs, including molecular engineering of NFAs and their device engineering will be thoroughly investigated. And the as-obtained research results will provide good guidance in developing high-efficiency PSCs from NFAs development and device studies.

采用非富勒烯受体的聚合物光伏(PSCs)近年来获得巨大的发展，单节二元给受体共混器件的光电转化效率已超过13%、三元光伏器件突破14%。针对当前非富勒烯PSCs器件效率进一步提升所面临的稠环电子受体结构设计难题，本项目拟对申请人近期成功开发的吡咯并二噻吩稠环电子受体深入结构优化，开展四层次分子工程：稠环供电子单元的共轭拓展和侧链工程、受电子端基匹配、供-受体单元间引入锁定分子构象的共轭基团；全面考察结构修饰对受体材料光谱吸收、结晶性、分子能级、带隙和固相聚集性能等影响；基于吸收互补和能级匹配的给受体配伍原则，遴选高性能聚合物给体制备光伏器件并优化，考察给受体结构及配伍对活性层形貌和光伏性能的影响，结合器件物理揭示高效率器件减少能量损失的机制；拓展其在三元和叠层器件应用，实现14%以上效率PSCs。在此基础上，深入研究影响非富勒烯PSCs性能的关键因素，为以后研制高效率器件提供坚实基础。

聚合物太阳能电池作为最具潜力的新型光伏技术，对于推动现代可持续性社会发展具有重要意义。本项目围绕申请人成功开发的吡咯并二噻吩稠环电子受体深入结构优化，开展了三个层次分子工程：稠环供电子单元的侧链工程、稠环供电子单元的非对称设计、非稠环供电子单元的设计；同时对受体材料结晶动力学和光伏器件优化、开展了卓有成效的研究工作；全面考察结构修饰对受体材料光谱吸收、结晶性、分子能级、带隙和固相聚集性能等影响；考察了给/受体结构及配伍对活性层形貌和光伏性能的影响，结合器件物理揭示高效率器件减少能量损失的机制，探索了非富勒烯受体在三元太阳能电池的应用，实现16.7%以上效率的单结光伏电池。研究所取得的系列研究成果，为非富勒烯受体的设计开发，推动低成本高效稳定有机太阳能电池的发展提供坚实的实验依据。