聚合物太阳能电池新型高效光伏材料的研究

Polymer solar cells (PSCs) have attracted great attentions in recent years, due to their advantages of low cost, light weight, easy fabrication and capability to be fabricated into flexible devices. The present researches on the PSCs are mainly focused on increasing power conversion efficiency (PCE) of the devices, and the key point to increase the PCE is the design and synthesis of high efficiency conjugated polymer donor and fullerene derivative acceptor photovoltaic materials. Actually, the photovoltaic materials for PSCs are complicated system containing two components (donor and acceptor) and with multi-parameters. We not only need to optimize the absorption spectra, electronic energy levels and charge carrier mobility of the donor and acceptor materials, but also need to consider their aggregation structure and the interaction between the donor and acceptor molecules. Therefore, in this project, we will design and synthesize the conjugated polymer donor materials with broader absorption, higher hole mobility and lower HOMO energy level by D-A copolymerization, two-dimensional conjugation with conjugated side chain and electron-withdrawing group substitution. And we will try to control and optimize the aggregation structures, the matchment and the interpenetrating network of the donor and acceptor by structural modification with different functional substituents, to get coordinated high efficiency donor and acceptor photovoltaic materials. The PCE of the PSCs based on our new photovoltaic materials will exceed 10% under the illumination of AM1.5G, 100 mW/cm2. This project will be of great importance for the theoretical studies and future applications of the photovoltaic materials and PSCs.

聚合物太阳能电池(PSC)具有成本低、重量轻、制作工艺简单、可制备成柔性器件等突出优点，近年来成为共轭聚合物光电子材料和器件领域的研究热点。新型光电活性层材料的设计与应用是获得高光电能量转换效率的关键途径，因此成为PSC领域的研究焦点之一。PSC的光电活性层是由二元组分（聚合物给体和有机分子受体）在特定微观形貌下组成的体系，不仅需要对给体和受体材料的吸收光谱、分子能级和载流子迁移率等参数进行分别优化，还需要考虑它们的聚集态结构以及它们之间的相互作用。为此，本项目拟通过对聚合物给体材料和有机受体材料的分子结构优化，在光电活性层中实现宽吸收、高迁移率和匹配的分子能级，调整给体和受体混合相的微观形貌，使它们之间的匹配性达到最优，最终使聚合物太阳能电池的能量转换效率突破10%，这将对聚合物光伏材料和聚合物太阳能电池的理论研究和实际应用具有非常重要的意义。

聚合物太阳电池具有重量轻、成本低、可通过印刷工艺制备大面积柔性器件等突出优点，已经成为一项具有重要应用前景的新型光伏技术，是目前倍受关注的前沿领域。本项目基于分子设计思想，对光伏材料的吸收光谱、分子能级和分子构象进行了系统、深入的调控，合成出大量性能优异的光伏材料。在此基础上，建立了分子结构与器件性能之间的构效关系，为设计新型的高效率光伏材料提供了实验依据。我们还深入研究了活性层聚集态结构对光伏器件性能的影响，获得了调控活性层形貌的有效方法。同时，结合界面工程和器件制备工艺的优化，成功制备出高效率的电池器件，并获得世界领先的光伏效率。此外，探索了绿色溶剂加工方法在电池制备中的应用，优化了大面积器件工艺，并且通过环境友好的加工方法制备了高效率的大面积器件，为聚合物太阳能电池迈向产业化奠定了基础。通过本项目的实施，我们获得了系统的、多方面的提升电池光伏性能的新方法，对聚合物太阳能电池的理论研究和实际应用具有重要的意义。