Hao Lianzheng, Li Zhipeng, Liu Ranran, Shao Zhipeng, Wang Li, Wang Xiao, Cui Guanglei, Pang Shuping
Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P. R. China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, P.R. China.
ACS Appl Mater Interfaces. 2022 Mar 16;14(10):12442-12449. doi: 10.1021/acsami.1c21800. Epub 2022 Mar 2.
The existence of the PbI phase in the perovskite film is normally inevitable because of the easy sublimation of the organic component during the crystallization process under a relatively high annealing temperature. However, excess PbI will cause significant degradation on open current voltage () and fill factor (FF) under continuous illumination. Here, we developed a pressure-assisted space-confinement (PASC) method to enhance the phase purity of the perovskite film fabricated by the two-step spin-coating method. It was found that high pressure is more conductive to lower the sublimation rate of the organic units, and the space confinement is more favorable for the Ostwald ripening. The combination of them can easily fabricate high-quality perovskite films with large crystal grains and eliminated PbI remnants. As expected, the efficiency of the solar cell was improved from 20.38 to 22.26%; more importantly, the operational stability of the corresponding device had a pronounced improvement, which remains over 85% of its initial efficiency after 500 h maximum power point tracking measurement. Based on this PASC method, a prototype PSC module (PSM) with an active area of 14 cm was also fabricated reaching an efficiency over 17%.
由于在相对较高的退火温度下结晶过程中有机成分易于升华，钙钛矿薄膜中PbI相的存在通常是不可避免的。然而，过量的PbI会在持续光照下导致开路电流电压（）和填充因子（FF）显著下降。在此，我们开发了一种压力辅助空间限制（PASC）方法，以提高通过两步旋涂法制备的钙钛矿薄膜的相纯度。研究发现，高压更有利于降低有机单元的升华速率，而空间限制更有利于奥斯特瓦尔德熟化。它们的结合能够轻松制备出具有大晶粒且消除了PbI残余物的高质量钙钛矿薄膜。正如预期的那样，太阳能电池的效率从20.38%提高到了22.26%；更重要的是，相应器件的运行稳定性有了显著提高，在进行500小时最大功率点跟踪测量后，其效率仍保持在初始效率的85%以上。基于这种PASC方法，还制备了一个有源面积为14平方厘米的原型PSC模块（PSM），其效率超过了17%。
