叠层器件是目前聚合物太阳能电池效率的保持者，极有希望实现商业化。但是叠层器件的研究正处于起步阶段，用于叠层器件的高性能宽带隙聚合物给体材料寥寥无几，这严重阻碍了聚合物太阳能电池的发展。本申请拟设计合成稠环喹喔啉、稠环氮三唑等几类多氮杂稠（杂）环受体结构，选择合适的给体单元，构筑高性能的宽带隙聚合物给体材料，拓展面向叠层器件应用的宽带隙聚合物给体材料的种类，进一步提升叠层器件的效率。本项目将系统研究多氮杂稠（杂）环受体结构中稠环核心大小、杂原子类型、侧链功能基团等对于材料基本物理性能及光伏性能的影响规律和作用机制，寻求解决保持材料宽能带隙，同时兼顾光谱吸收、载流子迁移率和光伏性能的关键科学问题。筛选综合性能优良的聚合物给体材料制作单结常规器件、单结反向器件、双结和多结反向叠层器件，优化制作条件，获得器件的高效率。本项目如果成功实施，预期器件效率可超过11%，进一步推动聚合物太阳能电池的发展。

Tandem device is the world record holder of the polymer solar cells (PSCs), and it is promissing to realize the commercialization of PSCs in the near future. However, the reasearch work of tandem device is still in its start-up step and the large band-gap polymer donors with high performance are very rare, which seriously hinders the development of PSCs. In this project, some kinds of multiaza-fused ring acceptor blocks, such as multi-quinoxaline and multi-benzotriazole, will be designed and synthesized to contruct efficient large band-gap conjugated polymer donors. These materials will extend the types of large band-gap polymers and further raise the efficiencies of tandem devices. We will also research systematically the effect of ring sizes, hetero atoms, functional side chains on the basic physical properties and photovoltaic properties and their active mechanisms. This will resolve the trade-off of the large band gap and the optical absorption, carrier mobility and photovoltaic properties in large band-gap polymers. Finally, we will select the good polymer donor materials to fabricate single-junction conventional devices, single-junction inverted devices as well as multi-junction inverted tandem devices. We believe the high efficiency will be obtained after the optimization of the fabrication conditions. When this project has been executed, the efficiency will be expected to exceed 11%, which can further promote the development of polymer solar cells.