Nature of Self-Trapped Exciton Emission in Zero-Dimensional Cs<sub>2</sub>ZrCl<sub>6</sub> Perovskite Nanocrystals
Yan‐Mei He, Siping Liu, Zehan Yao, Qian Zhao, Pavel Chábera, Kaibo Zheng, Bin Yang, Tõnu Pullerits, Junsheng Chen
Abstract
High Resolution Image Download MS PowerPoint Slide Low dimensional perovskite-inspired materials with self-tapped exciton (STE) emission have stimulated a surge of cutting-edge research in optoelectronics. Despite numerous efforts on developing versatile low-dimensional perovskite-inspired materials with efficient STE emissions, there is little emphasis on the intrinsic dynamics of STE-based broad emission in these materials. Here, we investigated the excited state dynamics in zero-dimensional (0D) Cs 2 ZrCl 6 nanocrystals (NCs) with efficient blue STE emission. By using femtosecond transient absorption (fs-TA) spectroscopy, the ultrafast STE formation process within 400 fs is directly observed. Then, the formed STEs relax to an intermediate STE state with a lifetime of ∼180 ps before reaching the emissive STE state with a lifetime of ∼15 μs. Our work offers a comprehensive and precise dynamic picture of STE emission in low-dimensional metal halides and sheds light on extending their potential applications.