理解多尺度形貌中的共混相结...制备高性能光伏电池（英文）_张明.pdf

Chem.J.Chinese Universities,2023,44(7),2023014720230147(1/11)CHEMICAL JOURNAL OF CHINESE UNIVERSITIES高 等 学 校 化 学 学 报研究论文理解多尺度形貌中的共混相结构以制备高性能光伏电池张明1，钟文楷1，钱诗赟1，吕博赛2，周冠清1，薛晓南1，周子春1，史志文2，朱磊1，张永明1，3，刘烽1，3（1.上海交通大学化学化工学院,变革性分子前沿中心,原位物质科学中心,氢科学中心，2.上海交通大学人工结构与量子控制教育部重点实验室,物理与天文学院,上海 200240；3.东岳未来氢能材料公司含氟功能膜材料国家重点实验室,淄博 256401）摘要 将PC71BM引入J51 N2200和PM6 Y6两个典型的有机光伏系统中,研究了共混相的性质.研究结果表明,共混相中的激子离解和载流子传输过程是影响器件光电转换效率的关键.在J51 N2200 PC71BM共混薄膜中,PC71BM在共混相内的聚集会引入能量势垒抑制空穴转移过程.同时,双纤维网络之间间隙的扩大限制了解离后的电子和空穴在共混区内的有效扩散,从而导致较为严重的复合和能量损失.而在PM6 Y6 PC71BM共混薄膜中,引入的PC71BM分子均匀分布在共混相中,并能与PM6和Y6分子较好地混合.同时,PC71BM的加入不会干扰Y6到PM6的空穴转移,并增强了共混相的双极性传输特性.这种形貌非常有优势,其中存在大量的给受体界面,且产生的电子和空穴可以迅速扩散,并在晶相中高速传输至电极.该结果揭示了在多尺度形貌调控中共混相结构的重要性,是下一阶段有机太阳能电池效率超过20%需要重点考虑的问题.关键词 共混相；多尺度形貌；有机光伏；光电转换效率中图分类号 O631 文献标志码 A doi：10.7503/cjcu20230147Understanding the Mixing Phase Structure in Multi-length-scale Morphology to Arrest High-performance Photovoltaic DevicesZHANG Ming1，ZHONG Wenkai1，QIAN Shiyun1，LYU Bosai2，ZHOU Guanqing1，XUE Xiaonan1，ZHOU Zichun1，SHI Zhiwen2，ZHU Lei1*，ZHANG Yongming1，3，LIU Feng1，3*（1.School of Chemistry and Chemical Engineering，Frontiers Science Center for Transformative Molecules，Insitu Center for Physical Science，Center of Hydrogen Science，2.Key Laboratory of Artificial Structures and Quantum Control，Ministry of Education，School of Physics and Astronomy，Shanghai Jiao Tong University，Shanghai 200240，China；3.State Key Laboratory of Fluorinated Functional Membrane Materials，Dongyue Future Hydrogen Energy Materials Company，Zibo 256401，China）Abstract The properties of the mixing phase are investigated in detail by introducing PC71BM into two typical organic photovoltaic blends J51 N2200 and PM6 Y6.It is found that the process of exciton dissociation and carrier 收稿日期：2023-03-29.网络首发日期：2023-05-18.联系人简介：朱 磊,男,博士,助理研究员,主要从事高性能有机光伏器件制备及表征等方面的研究.E-mail:刘 烽,男,博士,教授,主要从事有机光伏、同步辐射散射技术及高性能含氟功能膜材料开发等方面的研究.E-mail:基金项目：国家自然科学基金(批准号:51973110,22109094)和中国博士后科学基金(批准号:2022M722072,2022T150406)资助.Supported by the National Natural Science Foundation of China(Nos.51973110,22109094)and the China Postdoctoral Science Foundation (Nos.2022M722072,2022T150406).CHEMICAL JOURNAL OF CHINESE UNIVERSITIES高 等 学 校 化 学 学 报研究论文Chem.J.Chinese Universities,2023,44(7),2023014720230147(2/11)transport in the mixing zone play a key role in determining the power conversion efficiency.In J51 N2200 PC71BM blend，the aggregation of PC71BM in the mixing zone brings in energetic barrier to inhibit the hole transfer process.In the meanwhile，the enlarged intervals in-between the double fibril network limit the effective diffusion of the split electrons and holes in the mixing zone，leading to large recombination and energy loss.While in PM6 Y6 PC71BM blend，the introduced PC71BM could homogeneously distribute in the amorphous zone，mixing well with PM6 and Y6 molecules.Meanwhile，the addition of PC71BM does not perturb the hole transfer from Y6 to PM6.Such a morphology is advantageous where electrons and holes generated at abundant donor/acceptor interface could diffuse out rapidly，and transport in the crystalline pathway towards the corresponding electrodes.Such results reveal the importance of manipulating the mixing phase structure in the multi-length-scale morphology，of high demand towards 20%efficiency in the next episode organic solar cell（OSC）development.Keywords Mixing phase；Multi-length-scale morphology；Organic photovoltaics；Power conversion efficiency1 IntroductionIn the non-fullerene acceptor（NFA）based organic solar cells（OSCs），the crystallization and phase separation of the donor and acceptor materials form a bi-continuous nanoscale network，with complex multi-length-scale morphology to balance the exciton dissociation and charge transport，which play an important role to dictate the OSC performance110.For the binary OSCs，a typical morphology model includes crystalline donor phase，crystalline acceptor phase and a molecular mixing phase，which jointly establish the microscopic framework to suit the exciton nature in organic semiconductors.Currently，attention has been focused on the details of the crystalline structure，and its correlation with device performance1115，leaving the mixing phase property unexplored.It is also argued that the mixing zone in molecular level can be one of the most important domains，where charge generation and diffusion are strongly coupled with materials electronic and mixing properties and dictate open-circuit voltage（VOC），short-circuit current（JSC），and fill factor（FF）16.From the morphology aspect，this molecular mixture constructs the amorphous phase to bridge the crystalline domains，where the diffusion of the carriers generated at the abundant donor/acceptor interface is the key to determine the optoelectronic productivity17，18.Although important as it is claimed，the nature of the mixing zone is far from well understood，and it is urgent to study the localized morphology，exciton and carriers kinetics in the mixing zone to clarify how the mixing phase coordinated with