Han Gi Rim, An Mai Ngoc, Jang Hyunmin, Han Noh Soo, Kim JunWoo, Jeong Kwang Seob, Yoon Tai Hyun, Cho Minhaeng
Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul, Republic of Korea.
Quantum Science Ltd., Warrington, UK.
Nat Commun. 2025 May 28;16(1):4956. doi: 10.1038/s41467-025-60313-3.
By employing two synchronized mode-locked femtosecond lasers and interferometric detection of the pump-probe spectra-referred to as asynchronous and interferometric transient absorption-we have developed a method for broad dynamic range and rapid data acquisition. Using asynchronous and interferometric transient absorption, we examined photochemical changes during femtosecond pump-probe experiments on all-inorganic cesium lead halide nanomaterials. The laser pulse train facilitates photoreactions while allowing real-time observation of charge carrier dynamics. In perovskite nanocrystals undergoing photo-substitution of halide anions, transient absorption spectra showed increasing bandgap energy and faster relaxation dynamics as the Cl/Br ratio increased. For colloidal perovskite nanoplatelets, continuous observation revealed both spectral and kinetic changes during the light-induced coalescence of nanoplatelets, by analyzing temporal segments. This integrated technique not only deepens understanding of exciton dynamics and environmental influences in perovskite nanomaterials but also establishes asynchronous and interferometric transient absorption as a transformative tool for real-time observation of photochemical dynamics.
通过使用两台同步锁模飞秒激光器以及对泵浦-探测光谱进行干涉测量（即异步干涉瞬态吸收），我们开发出了一种具有宽动态范围和快速数据采集能力的方法。利用异步干涉瞬态吸收，我们在全无机铯铅卤化物纳米材料的飞秒泵浦-探测实验中研究了光化学变化。激光脉冲序列促进了光化学反应，同时允许实时观察电荷载流子动力学。在经历卤化物阴离子光取代的钙钛矿纳米晶体中，随着Cl/Br比例的增加，瞬态吸收光谱显示带隙能量增加且弛豫动力学加快。对于胶体钙钛矿纳米片，通过分析时间片段，连续观察揭示了纳米片光诱导聚结过程中的光谱和动力学变化。这种集成技术不仅加深了对钙钛矿纳米材料中激子动力学和环境影响的理解，还将异步干涉瞬态吸收确立为实时观察光化学动力学的变革性工具。
