The solution processability of photoactive halide perovskites differentiates them from traditional inorganic semiconducting materials that require multiple post-processing steps such as thermal/vacuum/blowing- and solvent-assisted treatment. Here we report a technical breakthrough of isothermally crystallizing high-quality perovskite films at room-temperature (RT) without the necessity of any post-processing. This process takes advantage of our discovery of a metastable intermediate of lower-dimensionality formed by amine-assisted crystallographic lattice expansion from an initial three-dimensional perovskite. Using in situ optoelectrical/chemical and ex situ structural characterizations, a detailed understanding of the low-dimensional metastable intermediate is developed. In conjunction with the metastable intermediate, the rapid evaporation of the solvent and amine facilitates ultra-fast crystallization at RT within seconds. This RT rapidly synthesized perovskite film exhibits a carrier diffusion length of 2.9 μm and {00} preferred orientation with an ultrahigh Lotgering factor of 97%. These films are highly compatible to conventional or inverted devices, demonstrating 22.3% and 23.1% power conversion efficiencies, respectively.

中文翻译：

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室温等温结晶钙钛矿

光敏卤化物钙钛矿的溶液可加工性使其与传统的无机半导体材料不同，传统的无机半导体材料需要多个后处理步骤，例如热/真空/吹塑和溶剂辅助处理。在这里，我们报道了在室温（RT）下等温结晶高质量钙钛矿薄膜的技术突破，而无需进行任何后处理。此过程利用了我们发现的低维亚稳中间物的优势，该中间物是由胺辅助晶体学晶格从初始三维钙钛矿形成的。使用原位光电/化学和非原位通过结构表征，对低维亚稳中间体进行了详细的了解。与亚稳中间体一起，溶剂和胺的快速蒸发有助于在数秒内在室温下超快速结晶。这种RT快速合成的钙钛矿薄膜表现出2.9μm的载流子扩散长度和{00 }较好的取向，超高Lotgering系数为97％。这些薄膜与常规或倒置器件高度兼容，分别具有22.3％和23.1％的功率转换效率。