Intermolecular interaction dynamics and optical dephasing: Picosecond photon echo measurements in mixed molecular crystals
Intermolecular interaction dynamics and optical dephasing: Picosecond photon echo measurements in mixed molecular crystals
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分子间相互作用动力学和光学相移：混合分子晶体中的皮秒光子回波测量
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
M. Fayer
中科院分区：
文献类型：
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作者：
D. Cooper;R. Olson;M. Fayer
利用皮秒光学相干技术研究了低浓度混合分子晶体中分子间的动态相互作用，并五苯的萘溶液。观察到光学均匀线的浓度依赖性加宽。受激光子回波测量排除了激发态传输的加宽机制。光子回波结果表现出线性浓度依赖性，并提出了一种理论，该理论解释了客体-客体偶极-偶极相互作用中声子诱导的波动的加宽。详细的考虑表明，该系统是最好的本地化的激发，而不是离域杂质带态。在低浓度极限，有额外的加宽的均匀线超出了寿命所产生的。提出了一个模型，根据客体-主体货车德瓦尔斯相互作用的声子诱导调制来描述这种加宽，即，在一个波动的晶体s.
Picosecond optical coherence techniques are employed to study dynamical intermolecular interactions in low concentration mixed molecular crystals, i.e., pentacene in naphthalene at 1.4 K. A concentration‐dependent broadening of the optical homogeneous line is observed. Stimulated photon echo measurements rule out excited state transport as the broadening mechanism. The photon echo results exhibit a linear concentration dependence and a theory is proposed that accounts for the broadening in terms of phonon‐induced fluctuations in guest–guest dipole–dipole interactions. Detailed considerations indicate that the system is best described in terms of localized excitations rather than delocalized impurity band states. In the low concentration limit, there is additional broadening of the homogeneous line beyond that produced by the lifetime. A model is presented describing this broadening in terms of phonon‐induced modulation of the guest–host van der Waals interactions, i.e., in terms of a fluctuating crystal s...