Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Leninskii Prosp. 31, Moscow 119991, Russia.
Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory 1/2, Moscow 119991, Russia.
Int J Mol Sci. 2022 Nov 1;23(21):13305. doi: 10.3390/ijms232113305.
Charge transport in crystalline organic semiconductors (OSCs) is considerably hindered by low-frequency vibrations introducing dynamic disorder in the charge transfer integrals. Recently, we have shown that the contributions of various vibrational modes to the dynamic disorder correlate with their Raman intensities and suggested a Raman-based approach for estimation of the dynamic disorder and search for potentially high-mobility OSCs. In the present paper, we showcase this approach by revealing the highest-mobility OSC(s) in two series of crystalline naphthalene diimide derivatives bearing alkyl or cycloalkyl substituents. In contrast to our previous studies, Raman spectra are not measured, but are instead calculated using periodic DFT. As a result, an OSC with a potentially high charge mobility is revealed in each of the two series, and further mobility calculations corroborate this choice. Namely, for the naphthalene diimide derivatives with butyl and cyclopentyl substituents, the estimated room-temperature isotropic electron mobilities are as high as 6 and 15 cm V s, respectively, in the latter case even exceeding 20 cm V s in a two-dimensional plane. Thus, our results highlight the potential of using the calculated Raman spectra to search for high-mobility crystalline OSCs and reveal two promising OSCs, which were previously overlooked.
在结晶有机半导体 (OSC) 中，电荷输运受到低频振动的极大阻碍，这些振动会在电荷转移积分中引入动态无序。最近，我们已经表明，各种振动模式对动态无序的贡献与其拉曼强度相关，并提出了一种基于拉曼的方法来估计动态无序并寻找潜在的高迁移率 OSC。在本文中，我们通过揭示带有烷基或环烷基取代基的两个系列结晶萘二酰亚胺衍生物中的最高迁移率 OSC 来展示这种方法。与我们之前的研究不同，这里不是测量拉曼光谱，而是使用周期性 DFT 进行计算。结果，在两个系列中都揭示了一种具有潜在高电荷迁移率的 OSC，进一步的迁移率计算也证实了这一选择。也就是说，对于带有丁基和环戊基取代基的萘二酰亚胺衍生物，估计的室温各向同性电子迁移率分别高达 6 和 15 cm V s，在后一种情况下，甚至在二维平面中超过 20 cm V s。因此，我们的结果强调了使用计算拉曼光谱来寻找高迁移率结晶 OSC 的潜力，并揭示了两个以前被忽视的有前途的 OSC。
