Wang Biao, Liu Fangzhou, Feng Fanxiu, Zhang Xian, Liang Yuchao, Wang Weiye, Guo Huichao, Guan Yan, Zhang Yangyang, Wu Cuncun, Zheng Shijian
Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology, School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300401, China.
College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Nano Lett. 2024 Apr 17;24(15):4512-4520. doi: 10.1021/acs.nanolett.4c00459. Epub 2024 Apr 5.
Perovskite nanocrystals are advantageous for interfacial passivation of perovskite solar cells (PSCs), but the insulating long alkyl chain surface ligands impede the charge transfer, while the conventional ligand exchange would possibly introduce surface defects to the nanocrystals. In this work, we reported novel in situ modification of CsPbBr nanocrystals using a short chain conjugated molecule 2-methoxyphenylethylammonium iodide (2-MeO-PEAI) for interfacial passivation of PSCs. Transmission electron microscopy studies with atomic resolution unveil the transformation from cubic CsPbBr to Ruddlesden-Popper phase (RPP) nanocrystals due to halogen exchange. Synergic passivation by the RPP nanocrystals and 2-MeO-PEA has led to suppressed interface defects and enhanced charge carrier transport. Consequently, PSCs with in situ modified RPP nanocrystals achieved a champion power conversion efficiency of 24.39%, along with an improvement in stability. This work brings insights into the microstructural evolution of perovskite nanocrystals, providing a novel and feasible approach for interfacial passivation of PSCs.
钙钛矿纳米晶体对钙钛矿太阳能电池（PSC）的界面钝化具有优势，但绝缘的长烷基链表面配体会阻碍电荷转移，而传统的配体交换可能会给纳米晶体引入表面缺陷。在这项工作中，我们报道了使用短链共轭分子2-甲氧基苯乙碘化铵（2-MeO-PEAI）对CsPbBr纳米晶体进行新颖的原位修饰，用于PSC的界面钝化。具有原子分辨率的透射电子显微镜研究揭示了由于卤素交换，立方相CsPbBr向Ruddlesden-Popper相（RPP）纳米晶体的转变。RPP纳米晶体和2-MeO-PEA的协同钝化导致界面缺陷得到抑制，电荷载流子传输增强。因此，原位修饰RPP纳米晶体的PSC实现了24.39%的最佳功率转换效率，同时稳定性也有所提高。这项工作为钙钛矿纳米晶体的微观结构演变提供了见解，为PSC的界面钝化提供了一种新颖且可行的方法。
