基于毛笔涂布的全溶液加工型有机太阳能电池及模组的研究

Organic solar cells have been attracting great attention because they can be fabricated from solutions with low cost, and easy to realize excellent mechanical flexibility, light weight, optical transparency, and different colors. Solution-based coating is considered to be an effective way to achieve large-area, low-cost organic solar cells with high-speed production. The current large-area coating techniques such as slot coating, inkjet printing and doctor blading typically have the drawbacks that the printing facilities are high and processing optimization is complicated. These limit the broad research and application of solution-processed low-cost organic solar cells. Here, the current proposal is to develop a new solution-processing technique of Chinese brush coating, and apply it for fully solution-processed organic solar cells. The research of the proposal include: (1) To investigate the effects of the category and size of the Chinese brushes, the concentration, the viscosity, printing speed, temperature of the substrates on the film thicknesses, crystallinity, morphology and optoelectronic properties; (2) To synergistically optimize the surface energy of the functional layers and the charge carrier transport and collection at the interfaces to realize the solution processing of the entire devices; (3) To achieve fully solution-processed organic solar cells and large-area (about 100 cm2) solar modules with the Chinese brush coating technique. This technique has the advantages of low cost, low loss of solutions, easy patterning, easy transfer to large-area modules, and the advantage of coating on non-horizontal surface. It is promising to become widely used in the fields of printed electronics and flexible electronics.

有机太阳能电池可溶液加工、潜在成本低，易于实现柔性、轻质、透明、多彩等优点，受到人们的广泛关注。溶液涂布印刷被认为是实现有机太阳能电池大面积、低成本、快速加工的有效手段。狭缝挤压涂布、喷墨打印、刮涂等技术存在设备成本高、工艺优化复杂的问题，限制了有机太阳能电池印刷研究的开展。本项目拟发展基于毛笔的印刷涂布技术，应用于全溶液加工型有机太阳能电池中，拟开展的研究内容包括：（1）研究毛笔的材质、粗细等内部因素以及溶液的浓度、粘度、印刷速度、基底温度等外部因素对功能层薄膜厚度、形态、光电性质的影响；（2）协同调节功能层表面能及界面处载流子传输收集以实现各功能层的全溶液制备；（3）利用该技术实现全印刷有机太阳能电池及大面积（约100 cm2）模组。毛笔印刷技术具有成本低、溶液利用率高、易于图案化、易于扩展至大面积模组，且在非水平表面涂布具有优势，可望在印刷电子学、柔性电子学领域被广泛应用。

有机太阳能电池具有质量轻、机械柔性优异、可印刷涂布制备的优点，作为轻质便携式能源、柔性易集成能源，具有广泛的应用前景。本项目以实现高效涂布型柔性有机太阳能电池为目标，从大面积有机太阳能电池的制备方法、溶液加工型有机太阳能电池界面间相互作用、大面积有机太阳能电池及模组三方面开展研究工作。取得的研究成果如下：（1）薄膜制备技术方面，开发出毛笔涂布技术和水转印技术制备有机太阳能电池薄膜，包含有机半导体活性层薄膜、电荷传输层薄膜和聚合物电极薄膜；（2）材料方面，厘清了低功函界面层PEI与非富勒烯活性层的相互作用，采用质子化策略钝化其与非富勒烯受体之间的反应，实现12.5%效率的柔性有机太阳能电池制备；开发出锌离子螯合聚乙烯亚胺（PEI-Zn）高效界面层，并将其应用于柔性有机太阳能电池；开发出溶液法空穴传输层材料HXMoO3，有效地改善PEDOT:PSS与活性层之间的电学接触；（3）器件方面，基于毛笔涂布技术制备了面积为18 cm2，效率为的6.3%有机太阳能电池模组；基于锌螯合聚乙烯亚胺（PEI-Zn）制备出15.0%效率的超柔有机太阳能电池；通过引入HXMoO3，制备出11.9%效率的全溶液加工型柔性有机太阳能电池；基于Ag网格/银纳米线（AgNWs）：PEI-Zn复合电极，实现了面积为54 cm2、效率为13.2%的柔性大面积太阳能电池。研究成果以华中科技大学为第一单位、项目负责人为通讯作者在Nat. Commun., Adv. Mater., Adv. Energy Mater., Adv. Funct. Mater.等期刊共发表论文30篇，申请专利3项（其中1项已授权）。所开发的导电复合材料、薄膜制备方法以及柔性有机太阳能电池具有应用前景，所厘清的界面相互作用及界面材料的开发对进一步开发新型界面材料、构建高效稳定性的有机太阳能电池具有指导意义。