Scientific Computing Laboratory, Institute of Physics Belgrade, University of Belgrade, Belgrade, Serbia.
Phys Chem Chem Phys. 2013 Mar 14;15(10):3543-51. doi: 10.1039/c3cp43115k. Epub 2013 Feb 4.
The comparison of hole density of states (DOS) and hole mobilities of several organic polymer based systems was performed to gain insight into the main factors that determine the electrical properties of conjugated polymers. The DOS and the mobility of the systems under investigation were evaluated using an atomistic multiscale procedure. The results suggest that the irregularities in the shape of the polymer chains increase the diagonal disorder, while alkyl side chains act as spacers that reduce the diagonal disorder which originates from long range electrostatic interactions. Intrachain electronic coupling in relatively ordered polymers narrows the tail of the DOS, while in less ordered polymers it represents the additional component of disorder and widens the tail of the DOS. The width of the DOS tail was confirmed to be an important factor that determines the activation energy for charge carrier transport. However, it is not the only factor since the system with a smaller width of the DOS tail can have a larger activation energy due to, for example, smaller wave function overlap between transport states.
为了深入了解决定共轭聚合物电性能的主要因素，对几种基于有机聚合物的体系的空穴态密度（DOS）和空穴迁移率进行了比较。使用原子尺度多尺度程序评估了所研究体系的 DOS 和迁移率。结果表明，聚合物链形状的不规则性增加了对角线无序，而烷基侧链作为间隔物，减少了源于长程静电相互作用的对角线无序。在相对有序的聚合物中，链内电子耦合会使 DOS 的尾部变窄，而在无序程度较低的聚合物中，它代表了无序的附加成分，并使 DOS 的尾部变宽。DOS 尾部的宽度被证实是决定载流子输运激活能的重要因素。然而，它不是唯一的因素，因为由于例如，在传输状态之间的波函数重叠较小，DOS 尾部较小的系统也可能具有较大的激活能。
