Anomalous Temperature Dependence of Exciton Spectral Diffusion in Tetracene Thin Film.,The Journal of Physical Chemistry Letters

当前位置： X-MOL 学术 › J. Phys. Chem. Lett. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Anomalous Temperature Dependence of Exciton Spectral Diffusion in Tetracene Thin Film.
The Journal of Physical Chemistry Letters ( IF 4.8 ) Pub Date : 2020-06-18 , DOI: 10.1021/acs.jpclett.0c01537
Tatsuya Yoshida ₁ , Kazuya Watanabe ₁ , Marin Petrović ₂ , Marko Kralj ₂

Affiliation

In this work, an ultrafast spectral diffusion of the lowest exciton in a tetracene ultrathin film is studied by two-dimensional electronic spectroscopy. From the analysis of the nodal line slope, the frequency-fluctuation correlation function (FFCF) of the exciton band is extracted. The FFCF contains two components with decay times of 400 and 80 fs; while the former can be understood by a linear exciton–phonon coupling model, the latter shows an order of magnitude increase in its amplitude from 96 to 186 K that cannot be explained by the same model. A novel scheme of the energy-gap fluctuations is examined, in which an intramolecular high-frequency mode causes the spectral diffusion that is enhanced through an anharmonic coupling to low-frequency phonon modes. This finding provides a valuable input for future theoretical predictions on the ultrafast nonadiabatic dynamics of the molecular exciton.

中文翻译：

Tetracene薄膜中激子光谱扩散的温度异常关系。

在这项工作中，通过二维电子光谱学研究了并四苯超薄膜中最低激子的超快光谱扩散。从节点线斜率的分析中，提取出激子带的频率波动相关函数（FFCF）。FFCF包含两个衰减时间分别为400和80 fs的分量。前者可以通过线性激子-声子耦合模型来理解，后者显示其幅度从96 K增大到186 K，幅度增加了一个数量级，无法用同一模型解释。研究了一种新的能隙波动方案，其中分子内高频模式引起频谱扩散，该频谱扩散通过非谐耦合至低频声子模式而增强。

更新日期：2020-07-02

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11