Xu Chenzhe, Chen Xiwen, Ma Shuangfei, Shi Mingyue, Zhang Suicai, Xiong Zhaozhao, Fan Wenqiang, Si Haonan, Wu Hualin, Zhang Zheng, Liao Qingliang, Yin Wanjian, Kang Zhuo, Zhang Yue
Academy for Advanced Interdisciplinary Science and Technology, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China.
Beijing Key Laboratory for Advanced Energy Materials and Technologies, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China.
Adv Mater. 2022 Apr;34(14):e2109998. doi: 10.1002/adma.202109998. Epub 2022 Feb 25.
Rubidium cation (Rb ) addition is witnessed to play a pivotal role in boosting the comprehensive performance of organic-inorganic hybrid perovskite solar cells. However, the origin of such success derived from irreplaceable superiorities brought by Rb remains ambiguous. Herein, grain-boundary-including atomic models are adopted for the accurate theoretical analysis of practical Rb distribution in perovskite structures. The spatial distribution, covering both the grain interiors and boundaries, is thoroughly identified by virtue of synchrotron-based grazing-incidence X-ray diffraction. On this basis, the prominent elevation of the halogen vacancy formation energy, improved charge-carrier dynamics, and the electronic passivation mechanism in the grain interior are expounded. As evidenced by the increased energy barrier and suppressed microcurrent, the critical role of Rb addition in blocking the diffusion pathway along grain boundaries, inhibiting halide phase segregation, and eventually enhancing intrinsic stability is elucidated. Hence, the linkage avalanche effect of occupied location dominated by subtle changes in Rb concentration on electronic defects, ion migration, and phase stability is completely investigated in detail, shedding a new light on the advancement of high-efficiency cascade-incorporating strategies and perovskite compositional engineering.
人们发现铷阳离子（Rb⁺）的添加在提升有机-无机杂化钙钛矿太阳能电池的综合性能方面起着关键作用。然而，这种成功源自铷所带来的不可替代的优势的根源仍不明确。在此，采用包含晶界的原子模型对钙钛矿结构中实际的铷分布进行精确的理论分析。借助基于同步加速器的掠入射X射线衍射，全面确定了覆盖晶粒内部和边界的空间分布。在此基础上，阐述了卤化物空位形成能的显著提高、电荷载流子动力学的改善以及晶粒内部的电子钝化机制。如增加的能垒和抑制的微电流所证明的，阐明了添加铷在阻断沿晶界的扩散途径、抑制卤化物相分离以及最终增强本征稳定性方面的关键作用。因此，详细全面地研究了铷浓度的细微变化主导的占据位置对电子缺陷、离子迁移和相稳定性的连锁雪崩效应，为高效级联掺入策略和钙钛矿组成工程的进展提供了新的思路。
