Untangling the Fundamental Electronic Origins of Non‐Local Electron–Phonon Coupling in Organic Semiconductors
Untangling the Fundamental Electronic Origins of Non‐Local Electron–Phonon Coupling in Organic Semiconductors
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DOI：
10.1002/adfm.202303701
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发表时间：
2023-05
影响因子：
19
通讯作者：
P. A. Banks;G. D’Avino;G. Schweicher;J. Armstrong;C. Ruzié;Jong Won Chung;Jeong‐Il Park;Chizuru Sawabe;T. Okamoto;J. Takeya;H. Sirringhaus;M. Ruggiero
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作者：
P. A. Banks;G. D’Avino;G. Schweicher;J. Armstrong;C. Ruzié;Jong Won Chung;Jeong‐Il Park;Chizuru Sawabe;T. Okamoto;J. Takeya;H. Sirringhaus;M. Ruggiero
具有独特分子性质和大载流子迁移率的有机半导体不断被开发出来，试图制造高效的电子材料。最近，具有独特结构修饰的设计分子已经被明确地开发出来，以抑制由低能声子模引起的固态分子运动，低能声子模通过电子-声子耦合独特地限制载流子的迁移率。然而，这种低频振动动力学往往涉及复杂的分子动力学，使得理解电子-声子耦合的潜在电子起源变得困难。在这项研究中，首先产生了一系列材料中电子-声子耦合的模式分辨图像，这些材料是专门为抑制有害振动效应而设计的。在此基础上，发展了一种基于晶体轨道哈密顿布居(COHP)分析的方法，以解决特定振动的惊人大的电子-声子耦合常数的起源-下至单个原子-轨道尺度，明确地详细描述了分子间波函数重叠被扰动的方式。总体而言，这种方法对较少研究的分子振动的意想不到的影响提供了全面的解释，揭示了分子设计的新方面，应该考虑这些方面来创造改进的有机半导体材料。
Organic semiconductors with distinct molecular properties and large carrier mobilities are constantly developed in attempt to produce highly‐efficient electronic materials. Recently, designer molecules with unique structural modifications have been expressly developed to suppress molecular motions in the solid state that arise from low‐energy phonon modes, which uniquely limit carrier mobilities through electron–phonon coupling. However, such low‐frequency vibrational dynamics often involve complex molecular dynamics, making comprehension of the underlying electronic origins of electron–phonon coupling difficult. In this study, first a mode‐resolved picture of electron–phonon coupling in a series of materials that are specifically designed to suppress detrimental vibrational effects, is generated. From this foundation, a method is developed based on the crystalline orbital Hamiltonian population (COHP) analyses to resolve the origins—down to the single atomic‐orbital scale—of surprisingly large electron–phonon coupling constants of particular vibrations, explicitly detailing the manner in which the intermolecular wavefunction overlap is perturbed. Overall, this approach provides a comprehensive explanation into the unexpected effects of less‐commonly studied molecular vibrations, revealing new aspects of molecular design that should be considered for creating improved organic semiconducting materials.