Department of Physics, University of Gothenburg, 41296 Gothenburg, Sweden.
J Chem Phys. 2010 Aug 21;133(7):074308. doi: 10.1063/1.3466925.
The large polycyclic aromatic hydrocarbon molecules coronene, benzo[GHI]perylene, and anthracene have been ionized with femtosecond laser pulses at low laser intensities and the ionization process studied with velocity map imaging spectroscopy, supplemented with ion yield measurements. The electron spectra of coronene and benzo[GHI]perylene are structureless. Based on fluence and pulse duration dependence measurements, it is shown that the electron spectra are not produced in field ionization processes, and the ionization mechanism is identified to be a quasithermal statistical electron emission, previously suggested for the fullerenes C(60) and C(70). The anthracene photoelectron spectra are dominated by above threshold ionization features, but with some indication of quasithermal ionization at longer pulses.
大的多环芳烃分子 Coronene、Benzo[GHI]perylene 和 Anthracene 已经被飞秒激光脉冲在低激光强度下离化，并通过速度图成像光谱学进行了研究，辅以离子产率测量。Coronene 和 Benzo[GHI]perylene 的电子能谱是无结构的。基于光强和脉冲持续时间的依赖性测量，表明电子能谱不是在场致电离过程中产生的，并且电离机制被确定为以前提出的富勒烯 C(60)和 C(70)的准热统计电子发射。Anthracene 的光电子能谱主要由阈上电离特征主导，但在较长脉冲下有一些准热电离的迹象。
