Department of Chemistry, Lehigh University.
Department of Chemistry, Pennsylvania State University - Altoona College;
J Vis Exp. 2024 Feb 16(204). doi: 10.3791/65519.
Transient absorption (TA) spectroscopy is a powerful time-resolved spectroscopic method used to track the evolution of excited-state processes through changes in the system's absorption spectrum. Early implementations of TA were confined to specialized laboratories, but the evolution of commercial turn-key systems has made the technique increasingly available to research groups across the world. Modern TA systems are capable of producing large datasets with high energetic and temporal resolution that are rich in photophysical information. However, processing, fitting, and interpreting TA spectra can be challenging due to the large number of excited-state features and instrumental artifacts. Many factors must be carefully considered when collecting, processing, and fitting TA data in order to reduce uncertainty over which model or set of fitting parameters best describes the data. The goal of data preparation and fitting is to reduce as many of these extraneous factors while preserving the data for analysis. In this method, beginners are provided with a protocol for processing and preparing TA data as well as a brief introduction to selected fitting procedures and models, specifically single wavelength fitting and global lifetime analysis. Commentary on a number of commonly encountered data preparation challenges and methods of addressing them is provided, followed by a discussion of the challenges and limitations of these simple fitting methods.
瞬态吸收（TA）光谱学是一种强大的时间分辨光谱方法，用于通过系统吸收光谱的变化来跟踪激发态过程的演变。早期的 TA 实现仅限于专业实验室，但商业交钥匙系统的发展使得该技术越来越多地为世界各地的研究小组所使用。现代 TA 系统能够以高能量和时间分辨率生成富含光物理信息的大型数据集。然而，由于激发态特征和仪器伪影数量众多，处理、拟合和解释 TA 光谱可能具有挑战性。为了减少哪种模型或拟合参数集最能描述数据的不确定性，在收集、处理和拟合 TA 数据时必须仔细考虑许多因素。数据准备和拟合的目标是在保留数据进行分析的同时，减少这些无关因素的数量。在这种方法中，初学者将获得处理和准备 TA 数据的协议，以及对选定拟合过程和模型的简要介绍，特别是单波长拟合和全局寿命分析。对一些常见的数据准备挑战以及解决这些挑战的方法进行了评论，随后讨论了这些简单拟合方法的挑战和局限性。
