在有机分子晶体中带状电荷传输和电子 - 声子合
Benjamin K Chang1, Marco Bernardi1
1Department of Applied Physics and Materials Science, California Institute of Technology, 1200 E California Blvd, Pasadena, California, 91125, UNITED STATES.
Journal of physics. Condensed matter : an Institute of Physics journal
|December 11, 2024
概括
有机分子晶体中高载体流动性对于应用至关重要. 这项研究揭示了低频声子散射限制了移动性,这表明应变工程可以提高有机半导体的性能.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 有机电子 有机电子
背景情况:
- 有机分子晶体 (OMC) 中的电荷传输和载体流动性对于电子应用至关重要.
- 由于复杂的晶体结构和电子-声子 (e-ph) 相互作用,预测和建模OMC中的载体流动性是复杂的.
研究的目的:
- 使用第一原则方法,准确计算各种OMC中的电子和孔载体运动.
- 阐明电子 - 声子相互作用,特别是低频模式在限制载体移动性的作用.
- 探索应变工程的潜力,以提高OMC的移动性.
主要方法:
- 在博尔兹曼运输方程 (BTE) 形式主义中运用了第一原理计算.
- 计算的e-ph相互作用,考虑所有音声模式和电子频段.
- 专注于带状,弱e-ph合传输系统.
主要成果:
- 在计算和实验中的,,四,五和双的移动性值之间取得了很好的一致性,在100-400K之间.
- 确定了低频 (LF) 声子 (<150 cm-1),主要是分子间振动,作为移动性限制的主要原因.
- 证明LF模式的散射率对应变敏感,表明应变工程是促进移动性的可行策略.
结论:
- 这项研究提供了一个强大的理论框架,用于理解OMC中的带状电荷传输.
- 低频声波模式显著影响载体的移动性,即使它们的e-ph合不是最强的.
- 应变工程提供了一个有前途的途径,通过调整e-ph相互作用来设计高流动性的有机半导体.
相关概念视频
02:58Crystal Field Theory - Octahedral Complexes
26.2K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.2K
01:16IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
1.2K
A covalently bonded heteronuclear diatomic molecule can be modeled as two vibrating masses connected by a spring. The vibrational frequency of the bond can be expressed using an equation derived from Hooke's law, which describes how the force applied to stretch or compress a spring is proportional to the displacement of the spring. In this case, the atoms behave like masses, and the bond acts like a spring.
According to Hooke's law, the vibrational frequency is directly proportional to...
According to Hooke's law, the vibrational frequency is directly proportional to...
1.2K
02:54Molecular and Ionic Solids
16.9K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
16.9K
02:35Band Theory
15.0K
When two or more atoms come together to form a molecule, their atomic orbitals combine and molecular orbitals of distinct energies result. In a solid, there are a large number of atoms, and therefore a large number of atomic orbitals that may be combined into molecular orbitals. These groups of molecular orbitals are so closely placed together to form continuous regions of energies, known as the bands.
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
The energy difference between these bands is known as the band gap.
Conductor, Semiconductor,...
15.0K
01:21Polymer Classification: Crystallinity
2.8K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.8K
02:40MO Theory and Covalent Bonding
10.3K
The molecular orbital theory describes the distribution of electrons in molecules in a manner similar to the distribution of electrons in atomic orbitals. The region of space in which a valence electron in a molecule is likely to be found is called a molecular orbital. Mathematically, the linear combination of atomic orbitals (LCAO) generates molecular orbitals. Combinations of in-phase atomic orbital wave functions result in regions with a high probability of electron density, while...
10.3K