Abstract There is always a surge of interest in compositional engineering to improve the performance of organic–inorganic halide perovskite (OIHP) solar cells among research communities. However, the role of dopant in OIHPs has not been clearly clarified so far. Relying on the slow growth of spaced-limited method, crystallization details of OIPH thin films can be amplified to explore the dopant distribution behavior easily. Herein, we optimized preparation conditions of spaced-limited method, and then conducted Bi3+ incorporation into MAPbBr3 single-crystalline thin films (SCTFs) to further explore its impacts from another angle. PTAA-modified substrate surfaces could accelerate the diffusion of precursor ions in the slit, which facilitated to obtain large area OIPH thin films. After Bi3+ incorporation, it’s easy to find that Bi3+ could gradually aggregate on the top surface of MAPbxBi1-xBr3 thin films to form a layer of brown materials (MAPbBr3 crystal grains containing high Bi3+ content). As Bi3+ concentration increased in precursor solution, Bi3+-based perovskite (MA3Bi2Br9) would finally separate. Bi3+ distribution behavior and growth mechanism of MAPbxBi1-xBr3 thin films can give more enlightenment for understanding the role of dopant ions in OIHPs for applications in modern electronics.

中文翻译：

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用空间限制法探索 MAPbxBi1-xBr3 薄膜的 Bi3+ 分布特性

摘要 一直以来，研究界对提高有机-无机卤化物钙钛矿 (OIHP) 太阳能电池性能的成分工程的兴趣激增。然而，掺杂剂在 OIHPs 中的作用迄今尚未明确。依靠空间限制法的缓慢生长，可以放大 OIPH 薄膜的结晶细节以轻松探索掺杂剂分布行为。在此，我们优化了空间限制法的制备条件，然后将 Bi3+ 掺入到 MAPbBr3 单晶薄膜（SCTFs）中，以从另一个角度进一步探讨其影响。PTAA修饰的衬底表面可以加速前体离子在狭缝中的扩散，有利于获得大面积的OIPH薄膜。Bi3+掺入后，很容易发现，Bi3+ 会逐渐聚集在 MAPbxBi1-xBr3 薄膜的顶面，形成一层棕色材料（MAPbBr3 晶粒含有高 Bi3+ 含量）。随着前体溶液中 Bi3+ 浓度的增加，Bi3+ 基钙钛矿 (MA3Bi2Br9) 最终会分离。MAPbxBi1-xBr3薄膜的Bi3+分布行为和生长机制可以为理解掺杂离子在OIHPs中的作用在现代电子学中的应用提供更多启示。