新型共轭支链间隔型D-A聚合物的合成及其光伏性能研究

Solar energy is recognized as the most abundant clean energy. Advantages of the polymer solar cells (PSCs) include low-cost fabrication of large-area devices, light-weight, mechanical flexibility, and easy tunability of the chemical properties of the polymer materials. Therefore, these advantages aroused great interests from academia to industries. As the most important part of PSCs, the polymeric donor materials should have high hole mobility, lower HOMO energy level, broad and strong absorption. Based on our recently works on side-chain isolated two dimensional conjugated polymers, and the benefits of the donor-acceptor structure, here, we proposed a new concept of the side chain isolated Donr-Acceptor two dimensional polymer. That is choosing proper acceptors containing π-bridge as side chain isolated group to modulate the energy levels, broaden the absorption, and promote the charge transfer between the polymer donor and the fullerene acceptors, which will helps to solve the problems such as low mobilities and poor absorptions. In our research, besides choosing PCBM as acceptors, we will also study the compatibility of our new polymer donors with high LUMO fullerene acceptor (such as ICBA), and their application as polymer donors in all polymer solar cells.

太阳能是公认的最丰富的清洁能源。聚合物太阳能电池的优点有低成本、易于加工、适于制备大面积柔性器件并且给体材料结构可调。正因为此，聚合太阳能电池正受到学术界、工业界的广泛关注。 而作为聚合物太阳能电池光敏活性层的主要组成部分，聚合物给体光伏材料，需要具有高空穴迁移率、较低的HOMO能级(最高占有轨道)和宽而强的吸收。在此，项目申请人在"支链间隔"两维聚合物的前期工作基础上，借鉴D-A 电荷转移概念，提出了新型"支链间隔型D-A 结构聚合物光伏材料"的设计思想：选用含有π桥的电子受体单元为支链间隔基团, 调节能级、扩大吸收、促进给受体间的电荷的转移，以解决高效光伏材料研发中吸光差，迁移率低的普遍问题。在光伏研究中，除选用广泛应用的富勒烯材料(PCBM) 做受体外，我们还将研究此类聚合物与高LUMO 能级受体(ICBA)的匹配性问题，以及探索此类材料作为给体材料在全聚合物的太阳能电池中的应用。

可溶液价格加工的聚合物太阳能电池，由于其具有价格低廉、柔性以及可印刷制备方面的优势，引起了越来越多的关注。在这个项目中，(1)合成了一系列基于苯并二噻吩-苯并三氮唑类的含有不同共轭侧链的中间带隙的聚合物。通过在苯并三氮唑单元上引入氟原子，以及侧链工程（硫烷基，硅烷基），所得聚合物与非富勒烯受体ITC匹配，获得了9−11%的高效率；(2)在ITIC受体上通过侧链异构化引入了间位取代的烷基苯，得到了m-ITIC，进一步将效率提升到了12%； (3) 通过将A-D-A 结构单元嵌入到聚合物主链中，提出了一种合成高效受体聚合物PZ1的新策略，获得了9.19%的能量转换效率。发表标注本项目资助的论文20篇，包括1篇《自然通讯》，1篇《德国应用化学》，2篇《美国化学会志》和3篇《先进材料》。