Zheng Kanghui, Liu Chang, Yu Kuibao, Meng Yuanyuan, Yin Xu, Bu Shixiao, Lin Shuyuan, Liu Cuirong, Ge Ziyi
Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, P. R. China.
College of Materials Technology and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, P. R. China.
ACS Appl Mater Interfaces. 2023 Mar 22;15(11):14748-14759. doi: 10.1021/acsami.2c19954. Epub 2023 Mar 10.
As an important part of perovskite solar cells (PSCs), hole transporting layer (HTL) has a critical impact on the performance and stability of the devices. In an attempt to alleviate the moisture and thermal stability issues from the commonly used HTL Spiro-OMeTAD with dopant, it is urgent to develop novel HTLs with high stability. In this study, a new class of polymers D18 and D18-Cl are applied as undoped HTL for CsPbIBr-based PSCs. In addition to the excellent hole transporting properties, we unveil that D18 and D18-Cl with larger thermal expansion coefficient than that of CsPbIBr could impose a compressive stress onto the CsPbIBr film upon thermal treatment, which could release the residual tensile stress in the film. As a result, the efficiency of CsPbIBr-based PSCs with D18-Cl as HTL reaches 16.73%, and the fill factor (FF) exceeds 85%, which is one of the highest FF records for the conventional-structured device to date. The devices also show impressive thermal stability with over 80% of the initial PCE retained after 85 °C heating for 1500 h.
作为钙钛矿太阳能电池（PSC）的重要组成部分，空穴传输层（HTL）对器件的性能和稳定性有着至关重要的影响。为了缓解常用的含掺杂剂的HTL Spiro-OMeTAD存在的湿度和热稳定性问题，迫切需要开发具有高稳定性的新型HTL。在本研究中，一类新型聚合物D18和D18-Cl被用作基于CsPbIBr的PSC的无掺杂HTL。除了优异的空穴传输性能外，我们还发现，热膨胀系数比CsPbIBr大的D18和D18-Cl在热处理时会对CsPbIBr薄膜施加压应力，从而释放薄膜中的残余拉应力。结果，以D18-Cl作为HTL的基于CsPbIBr的PSC的效率达到16.73%，填充因子（FF）超过85%，这是迄今为止传统结构器件中最高的FF记录之一。这些器件还表现出令人印象深刻的热稳定性，在85°C加热1500小时后仍保留超过80%的初始光电转换效率（PCE）。
