用于构建高性能有机光伏电池的共轭聚合物阳极界面层材料

In recent years, the power conversion efficiency of organic solar cells (OSC) has been boosted remarkably, but a further breakthrough in photovoltaic efficiency strongly depended on the development of anode interfacial layer (AIL) materials. Conjugated polymers have played an important role in serving as AIL materials due to their good thermal stability, excellent film-forming ability and superior charge carrier transport property. However, current AIL materials generally possess low work function as well as low optical transmittance; this severely limits their modification performances in OSCs. This project focuses on the designs and syntheses of self-doped and undoped conjugated polymers as AIL materials. By synergistically modulating the energy level structure and the hole transport property of conjugated polymers, novel AIL materials with high work function and superior hole mobility will be obtained. Using the as-synthesized conjugated polymer as AIL materials in the fabrication of OSCs, open-circuit voltage, short-circuit current, fill factor and external quantum efficiency of the device can be simultaneously improved, leading to a breakthrough of efficiency enhancement in OSCs. Meanwhile, the relationship of the chemical composition and structure with the AIL modification performance of the materials could be established by studying in depth the AIL action mechanism combined with theoretical computation. These results from this project will be of theoretical and practical significance for the field of organic photovoltaics.

近年来，有机太阳电池在光伏效率方面得到显著提升，但是，实现光伏效率的进一步突破迫切地需要高性能阳极界面层材料的发展。共轭聚合物具有良好的热稳定性、成膜性和载流子传输性能，在光伏器件阳极修饰方面具有重要的应用潜力。然而，目前的聚合物阳极界面层材料存在功函数低和光响应区间的光透过率偏低的问题，限制了界面层修饰性能的进一步提升。本项目从自掺杂型和本征态共轭聚合物的设计合成入手，对聚合物能级结构和空穴传输性能进行协同调制，获得同时具有高功函数和高空穴迁移率的阳极界面层材料，提高阳极界面层的综合修饰性能。利用所合成的聚合物阳极界面层材料制备高效率器件，使器件的开路电压、短路电流、填充因子和外量子效率等参数得到全面提升，以实现器件光伏效率的突破。同时，结合理论计算深入研究界面修饰作用机理，揭示材料的化学组成、结构和修饰性能的构效关系。本项目的研究结果对有机光伏的理论研究和实际应用具有重要的意义。

有机光伏电池（OPV）具有重量轻、柔性、易于通过廉价的印刷工艺制备大面积器件等优点，受到国内外的广泛关注。但是，OPV电池的阳极界面层（AIL）材料的种类和数量都相对较少，很多传统AIL已经不适合用于制备高性能的器件，限制了领域的进一步发展。本项目围绕解决“AIL与活性层光电特性失配、难以通过溶液法大面积制备”的关键问题开展了系统研究，对AIL材料的吸收光谱、分子能级和电导率进行了系统、深入的调控，并发展出全新的“互掺杂”材料设计原理，合成出大量性能优异的AIL材料。我们还深入研究了阳极界面层光电特性对OPV电池性能的影响，成功制备出高效率的器件。此外，开发出具有抗紫外光、抗水汽侵蚀功能的新型界面层材料，探索出利用界面层提高OPV电池稳定性的新方法，获得了器件使用寿命方面的突破，为OPV电池迈向产业化奠定了基础。通过本项目的实施，我们获得了大范围协同调控半导体材料多种光电特性参数的新方法，开发出的高性能AIL材料对OPV电池的理论研究和实际应用具有重要意义。