Department of Chemistry , University of Liverpool , Liverpool L69 3BX , U.K.
School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
J Chem Theory Comput. 2018 Jul 10;14(7):3752-3762. doi: 10.1021/acs.jctc.8b00235. Epub 2018 Jun 13.
A substantial amount of evidence indicates a relevant role played by the nonlocal electron-phonon couplings in the mechanism of charge transport in organic semiconductors. In this work, we compute the nonlocal electron-phonon coupling for the prototypical molecular semiconductors rubrene and tetracene using the phonon modes obtained from ab initio methods. We do not make the rigid molecular approximation allowing a mixing of intra- and intermolecular modes, and we use a supercell approach to sample the momentum space. Indeed, we find that some low-frequency intramolecular modes are mixed with the rigid-molecule translations and rotations in the modes with the strongest electron-phonon coupling. To rationalize the results we propose a convenient decomposition of the delocalized lattice modes into molecular-based modes.
大量证据表明，非局域电子-声子耦合在有机半导体中的电荷输运机制中起着重要作用。在这项工作中，我们使用从头计算方法获得的声子模式来计算典型分子半导体苝和并四苯的非局域电子-声子耦合。我们不采用刚性分子近似，允许分子内和分子间模式混合，并且我们使用超胞方法来对动量空间进行采样。实际上，我们发现一些低频分子内模式与具有最强电子-声子耦合的刚性分子平移和旋转混合。为了合理化这些结果，我们提出了一种将离域晶格模式分解为基于分子的模式的方便方法。
