Xiang Xuwu, Wang Yan, Cao Qin, Zhou Jie
School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
ACS Appl Mater Interfaces. 2024 Dec 18;16(50):69180-69186. doi: 10.1021/acsami.4c13209. Epub 2024 Oct 7.
Due to the limitation of the diffusion kinetics of organic amine salts on the PbI layer in the two-step method, prepared perovskite particles are small in size, have many defects, and are randomly oriented, and the cell efficiency and stability are difficult to guarantee due to PbI residues. Here, we added a volatile additive, ,,','-tetramethylethylenediamine (TMEDA), to the PbI precursor solution and formed preaggregated atomic clusters with PbI through TMEDA, which reduced the Gibbs free energy of nucleation to obtain a porous PbI layer, and finally obtained a perovskite film with large particles, few defects, ideal crystal plane orientation, and no additive residues. The results show that the photoelectric conversion efficiency of the optimized device is increased by 1.68% (from 21.68% to 23.36%), and the unpackaged optimized device still maintains the maximum efficiency of 77% after being placed in the air for 1200 h. This study provides an effective way to fabricate efficient and stable perovskite solar cells by promoting the nucleation-induced crystallization orientation by volatile additives.
由于两步法中有机胺盐在PbI层上的扩散动力学限制，制备的钙钛矿颗粒尺寸小、缺陷多且取向随机，并且由于PbI残留，电池效率和稳定性难以保证。在此，我们向PbI前驱体溶液中添加了挥发性添加剂，N,N,N',N'-四甲基乙二胺（TMEDA），并通过TMEDA与PbI形成预聚集的原子簇，降低了成核的吉布斯自由能以获得多孔PbI层，最终得到了具有大颗粒、少缺陷、理想晶面取向且无添加剂残留的钙钛矿薄膜。结果表明，优化后的器件光电转换效率提高了1.68%（从21.68%提高到23.36%），未封装的优化器件在空气中放置1200小时后仍保持77%的最高效率。本研究提供了一种通过挥发性添加剂促进成核诱导结晶取向来制备高效稳定钙钛矿太阳能电池的有效方法。
