Vibronic line shapes of PTCDA oligomers in helium nanodroplets.
Vibronic line shapes of PTCDA oligomers in helium nanodroplets.
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氦纳米液滴中 PTCDA 低聚物的振动线形状。
DOI：
10.1063/1.3526749
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
F. Stienkemeier
中科院分区：
文献类型：
--
作者：
Jan J J Roden;A. Eisfeld;M. Dvořák;O. Bünermann;F. Stienkemeier
用氦纳米液滴分离光谱研究了有机半导体3,4,9,10-苝-四羧基二酐，C(24)H(8)O(6) （PTCDA）的低聚物。相对于单体吸收光谱，低聚物光谱表现出明显的分离，非常尖锐的吸收谱线，我们发现低聚物光谱由三个主峰组成，它们的表观宽度比单体谱线的宽度大几个数量级。使用一个简单的理论模型，其中一个弗伦克尔激子耦合到单体的内部振动模式，这些实验结果得到了很好的再现。仅考虑PTCDA分子的一种有效振动模式，就可以得到低聚物光谱中的三个峰。包含更多的振动模式导致准连续光谱，类似于广泛的低聚物光谱。
Oligomers of the organic semiconductor 3,4,9,10-perylene-tetracarboxylic-dianhydride, C(24)H(8)O(6) (PTCDA) are studied by means of helium nanodroplet isolation spectroscopy. In contrast to the monomer absorption spectrum, which exhibits clearly separated, very sharp absorption lines, it is found that the oligomer spectrum consists of three main peaks having an apparent width orders of magnitude larger than the width of the monomer lines. Using a simple theoretical model for the oligomer, in which a Frenkel exciton couples to internal vibrational modes of the monomers, these experimental findings are nicely reproduced. The three peaks present in the oligomer spectrum can already be obtained taking only one effective vibrational mode of the PTCDA molecule into account. The inclusion of more vibrational modes leads to quasicontinuous spectra, resembling the broad oligomer spectra.