Zhu Weidong, Yu Tao, Li Faming, Bao Chunxiong, Gao Hao, Yi Yong, Yang Jie, Fu Gao, Zhou Xiaoxin, Zou Zhigang
National Laboratory of Solid State Microstructures & Eco-Materials and Renewable Energy Research Center (ERERC), Department of Physics, Nanjing University, Nanjing 210093, P. R. China.
Nanoscale. 2015 Mar 12;7(12):5427-34. doi: 10.1039/c5nr00225g.
A high-quality CH3NH3PbI3 film is crucial in the manufacture of a high-performance perovskite solar cell. Here, a recrystallization process via facile fumigation with DMF vapor has been successfully introduced to self-repair of CH3NH3PbI3 films with poor coverage and low crystallinity prepared by the commonly used one-step spin-coating method. We found that the CH3NH3PbI3 films with dendritic structures can spontaneously transform to the uniform ones with full coverage and high crystallinity by adjusting the cycles of the recrystallization process. The mesostructured perovskite solar cells based on these repaired CH3NH3PbI3 films showed reproducible optimal power conversion efficiency (PCE) of 11.15% and average PCE of 10.25±0.90%, which are much better than that of devices based on the non-repaired CH3NH3PbI3 films. In addition, the hysteresis phenomenon in the current-voltage test can also be effectively alleviated due to the quality of the films being improved in the optimized devices. Our work proved that the fumigation of solvent vapor can modify metal organic perovskite films such as CH3NH3PbI3. It offers a novel and attractive way to fabricate high-performance perovskite solar cells.
高质量的CH3NH3PbI3薄膜对于高性能钙钛矿太阳能电池的制造至关重要。在此，通过用DMF蒸汽进行简便熏蒸的重结晶过程已成功引入，用于对通过常用的一步旋涂法制备的覆盖度差且结晶度低的CH3NH3PbI3薄膜进行自修复。我们发现，具有树枝状结构的CH3NH3PbI3薄膜可以通过调整重结晶过程的循环次数自发转变为覆盖完全且结晶度高的均匀薄膜。基于这些修复后的CH3NH3PbI3薄膜的介观结构钙钛矿太阳能电池显示出可重复的最佳功率转换效率（PCE）为11.15%，平均PCE为10.25±0.90%，这远优于基于未修复的CH3NH3PbI3薄膜的器件。此外，由于优化后的器件中薄膜质量得到改善，电流-电压测试中的滞后现象也能得到有效缓解。我们的工作证明，溶剂蒸汽熏蒸可以改性金属有机钙钛矿薄膜，如CH3NH3PbI3。它为制造高性能钙钛矿太阳能电池提供了一种新颖且有吸引力的方法。
