Fu Qiang, Liu Hang, Li Shitong, Zhou Tong, Chen Mingqian, Yang Yang, Wang Jian, Wang Rui, Chen Yongsheng, Liu Yongsheng
The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, College of Chemistry and Renewable Energy Conversion and Storage Center (RECAST), Nankai University, Tianjin, 300071, China.
The Institute of Seawater Desalination and Multipurpose Utilization, Ministry of Natural Resources (Tianjin), Tianjin, 300192, P. R. China.
Angew Chem Int Ed Engl. 2022 Oct 24;61(43):e202210356. doi: 10.1002/anie.202210356. Epub 2022 Aug 30.
The dominant hole transport material (HTM) in state-of-the-art perovskite solar cells (PSCs) is Spiro-OMeTAD, which needs to be doped using hydrophilic dopants to improve its hole mobility and conductivity, resulting in inferior device stability. Here, we propose an effective molecular design strategy to construct dopant-free polymer HTMs by selecting four structurally related polymers and investigating their structure-property relationship. It is found that the donor and acceptor units with longitudinal conjugate extension, such as BDT-T and BDD, could not only enhance the planarity of the conjugated polymer backbone and tune the energy levels but also promote the face-on orientation, resulting in superior charge extraction and transport. The optimized device utilizing dopant-free polymer HTM shows a high open-circuit voltage of 1.19 V and a champion efficiency of 24.04 % with greatly improved operational stability, making it among the best performance PSCs based on dopant-free HTMs.
在目前最先进的钙钛矿太阳能电池（PSC）中，占主导地位的空穴传输材料（HTM）是Spiro-OMeTAD，它需要使用亲水性掺杂剂进行掺杂以提高其空穴迁移率和电导率，这会导致器件稳定性较差。在此，我们提出一种有效的分子设计策略，通过选择四种结构相关的聚合物并研究它们的结构-性能关系来构建无掺杂剂的聚合物HTM。研究发现，具有纵向共轭延伸的供体和受体单元，如BDT-T和BDD，不仅可以增强共轭聚合物主链的平面性并调节能级，还可以促进面取向，从而实现优异的电荷提取和传输。利用无掺杂剂聚合物HTM优化后的器件显示出1.19 V的高开路电压和24.04 %的最佳效率，并且其运行稳定性得到了极大提高，使其成为基于无掺杂剂HTM的性能最佳的PSC之一。
