Molecular Origin of the Charge Carrier Mobility in Small Molecule Organic Semiconductors
Molecular Origin of the Charge Carrier Mobility in Small Molecule Organic Semiconductors
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DOI：
10.1002/adfm.201601807
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发表时间：
2016-08-01
影响因子：
19
通讯作者：
Wenzel, Wolfgang
中科院分区：
文献类型：
--
作者：
Friederich, Pascal;Meded, Velimir;Wenzel, Wolfgang
小分子有机半导体应用范围广泛，从有机发光二极管到有机光致发光器件。然而，低载流子迁移率严重限制了它们的潜力，例如，用于大面积设备。许多因素决定迁移率，例如分子堆积、电子结构、偶极矩和极化率。目前，定量从头计算模型来评估这些分子依赖性的影响是缺乏的。在这里，提出了一个多尺度模型，它提供了一个准确的预测超过十个数量级的迁移率的实验数据，并允许分解成分子的具体数量的载流子迁移率。分子特定的定量措施提供了两个单分子的性质，构象上的轨道能量的依赖性，和偶极诱导的极化确定空穴传输材料的流动性。基于第一性原理的模型计算有机半导体的关键性能特性的可用性可以使许多化合物的硅筛选用于开发高效的光电子器件。
Small-molecule organic semiconductors are used in a wide spectrum of applications, ranging from organic light emitting diodes to organic photovoltaics. However, the low carrier mobility severely limits their potential, e.g., for large area devices. A number of factors determine mobility, such as molecular packing, electronic structure, dipole moment, and polarizability. Presently, quantitative ab initio models to assess the influence of these molecule-dependent properties are lacking. Here, a multiscale model is presented, which provides an accurate prediction of experimental data over ten orders of magnitude in mobility, and allows for the decomposition of the carrier mobility into molecule-specific quantities. Molecule-specific quantitative measures are provided how two single molecule properties, the dependence of the orbital energy on conformation, and the dipole-induced polarization determine mobility for hole-transport materials. The availability of first-principles based models to compute key performance characteristics of organic semiconductors may enable in silico screening of numerous chemical compounds for the development of highly efficient optoelectronic devices.