Electron-vibrational interactions play a key role in limiting charge mobility in organic semi-conductors. This paper reports a theoretical study of the electron—phonon interaction in the 5,5′-diphenyl-2,2′-bitiophene (PTTP) molecule, which belongs to the class of thiophene-phenylene cooligomers, which are of great interest for organic optoelectronics due to their electron-transport and luminescent properties; these results are compared with anthracene, which is a model organic semiconductor. The contributions of various vibrational modes to the reorganization energy of PTTP and the anthracene molecules are revealed and it is shown that these contributions correlate with the intensities of the corresponding bands in the Raman spectrum. In particular, it is found that for the PTTP molecule the so-called I-mode with a frequency of ∼1460 cm⁻¹, which corresponds to collective vibration of atoms of all oligomer units, has the highest intensity in both spectra. These results indicate the promise of Raman spectroscopy for studying electron-vibrational interactions in organic semiconductors. Finally, the mobility of holes in PTTP and anthracene is estimated in the framework of the jump model and the reasons for their difference are analyzed. Based on these results, we propose some ways to reduce the electron-vibrational interaction in thiophene—phenylene cooligomers, which is important for the directional molecular design of organic semiconductors.

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噻吩-亚苯基冷聚体中的电子振动相互作用及其与拉曼光谱的关系

电子-振动相互作用在限制有机半导体中的电荷迁移率中起关键作用。本文报道了有关5,5'-联苯-2,2'-联苯噻吩（PTTP）分子中电子-声子相互作用的理论研究，该分子属于噻吩-亚苯基共聚低聚物，这对有机物非常重要光电子学由于其电子传输和发光特性；将这些结果与模型有机半导体蒽进行了比较。揭示了各种振动模式对PTTP和蒽分子重组能的贡献，并表明这些贡献与拉曼光谱中相应谱带的强度相关。特别是，发现对于PTTP分子，频率约为1460 cm的所谓I型^-1对应于所有低聚物单元的原子的集体振动，在两个光谱中强度最高。这些结果表明拉曼光谱技术有望用于研究有机半导体中的电子振动相互作用。最后，在跳跃模型的框架内估计了PTTP和蒽中空穴的迁移率，并分析了它们产生差异的原因。基于这些结果，我们提出了一些减少噻吩-亚苯基冷聚物中电子振动相互作用的方法，这对于有机半导体的定向分子设计很重要。