水醇溶近红外小分子受体材料的设计合成及光伏性能研究

Organic solar cells (OSCs) is believed to be one of promising candidates for next generation technology platforms due to its many advantages such as lightweight, flexibility, large area printing production, inexpensive and etc. However, the film forming process for high efficiency OSCs almost exclusively involved with toxic organic solvents. From the perspective of high throughput industrial manufacturing, using toxic organic solvents in the fabrication of OSCs will not only increase the cost for production, but be also harmful to the health of the workers, and is undesirable from the perspective of the environment. Thus, growing efforts should be made on developing environmentally friendly solution processed materials for OSCs. The water-alcohol soluble technology can render the materials good solubility in water or alcohols and other green solvents, which can overcome the challenge of using toxic organic solvents in devices fabrication. But the ionization state of the polar pendant groups of water-soluble organic materials has a significant impact on the device performance, which is found to be hole trapping induced by the polar end groups. In this proposal, we will design and synthesize a series of water-alcohol soluble small molecule acceptors with near-infrared absorption and water-alcohol soluble donor materials. We will explore the deep factors causing charge traps and develop new methods to suppress the traps by rationally manipulating the ionization state of the polar groups, which may minimize the hole trapping process. On the basis of systematical and in-depth study of the internal relations of “chemical structure-device performance”, we plan to develop novel high-performance water alcohol soluble active materials, followed by the development of highly-efficient OSCs which are processed by environment-friendly solvents. Through the joint study of material synthesis, device fabrication, and device physics, we are possible to make breakthrough in the development of novel water alcohol soluble photoactive materials and devices, which will contribute greatly to the development of low-cost, highly-efficient renewable energy technology of our country.

有机太阳电池因具有质轻、柔性、可大面积印刷制备及低成本等优势被认为是具有重大产业前景的新一代绿色能源技术。然而，有机太阳电池器件加工过程中常使用有毒有机溶剂，对人和环境有造成危害的风险，不利于大规模生产。因此，开发新型可绿色溶剂加工的有机光伏材料至关重要。水醇溶技术可赋予有机共轭材料溶于水或醇等绿色溶剂的特性，有效避免有毒溶剂的使用，但水醇溶活性层材料上侧链极性基团的氧化电位对器件性能有重大影响，易造成载流子陷阱，影响材料的电荷分离和传输。基于此，本项目拟合成一系列水醇溶近红外小分子受体材料和水醇溶聚合物给体材料，通过调控侧链极性基团的氧化电位，探索造成电荷陷阱的深层因素，发展抑制电荷中陷阱态的新方法。通过系统的分子设计工程与材料、器件物理研究，深入探索材料结构-器件性能内在联系，发展高效可绿色溶剂加工的有机太阳电池器件。为国家的新型低成本、高效率的可再生能源新技术的发展做出贡献。

有机太阳电池的吸收与能级可调控、形貌稳定、机械性能好等优势，使其极具产业化前景。其中，作为活性层组分之一的小分子受体是非富勒烯有机太阳电池性能的主要决定因素之一。本项目围绕非富勒烯小分子受体这个大主题，开发了一系列非富勒烯近红外小分子受体，包括非对称Y-型小分子受体和卟啉类小分子受体材料，最高器件效率超过15%，当器件面积为1cm2时，效率依然可以达到15%，展现出较好的适用性。另外，以天然产物腺嘌呤为侧链的小分子受体材料表现出良好的溶解性，效率接近9%。这些工作极大地提升了有机太阳电池的效率并为设计新型非富勒烯小分子受体材料提供了指导。此外，首次将基于腺嘌呤为侧链的聚合物用作光催化剂表现出优异的析氢性能，这一重要发现，为今后合成更高效的有机光催化剂提供了参考。