Jemli Khaoula, Diab Hiba, Lédée Ferdinand, Trippé-Allard Gaelle, Garrot Damien, Geffroy Bernard, Lauret Jean-Sébastien, Audebert Pierre, Deleporte Emmanuelle
Laboratoire Aimé Cotton, Ecole Normale Supérieure de Cachan, CNRS, Université Paris-Sud, Université Paris-Saclay, Bât 505 Campus d'Orsay, 91405 Orsay, France.
Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires de l'Ecole Normale Supérieure de Cachan, 61 Avenue du Président Wilson, 94235 Cachan, France.
Molecules. 2016 Jul 8;21(7):885. doi: 10.3390/molecules21070885.
Investigating the stability and evaluating the quality of the CH₃NH₃PbI₃ perovskite structures is quite critical both to the design and fabrication of high-performance perovskite devices and to fundamental studies of the photophysics of the excitons. In particular, it is known that, under ambient conditions, CH₃NH₃PbI₃ degrades producing some PbI₂. We show here that low temperature Photoluminescence (PL) spectroscopy is a powerful tool to detect PbI₂ traces in hybrid perovskite layers and single crystals. Because PL spectroscopy is a signal detection method on a black background, small PbI₂ traces can be detected, when other methods currently used at room temperature fail. Our study highlights the extremely high stability of the single crystals compared to the thin layers and defects and grain boundaries are thought to play an important role in the degradation mechanism.
研究CH₃NH₃PbI₃钙钛矿结构的稳定性并评估其质量，对于高性能钙钛矿器件的设计与制造以及激子光物理的基础研究都至关重要。特别是，众所周知，在环境条件下，CH₃NH₃PbI₃会降解生成一些PbI₂。我们在此表明，低温光致发光（PL）光谱是检测混合钙钛矿层和单晶中PbI₂痕量的有力工具。由于PL光谱是一种在黑色背景上的信号检测方法，当目前在室温下使用的其他方法失效时，小的PbI₂痕量也能被检测到。我们的研究突出了单晶与薄层相比具有极高的稳定性，并且缺陷和晶界被认为在降解机制中起重要作用。
