Jiang Yuqian, Zhong Xinxin, Shi Wen, Peng Qian, Geng Hua, Zhao Yi, Shuai Zhigang
MOE Key Laboratory of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084, China.
Nanoscale Horiz. 2016 Jan 18;1(1):53-59. doi: 10.1039/c5nh00054h. Epub 2015 Oct 21.
The experimental carrier mobility value of organic semiconductors has been increasing rapidly in recent years to well exceed the theoretical limit based on the hopping model calculated using the semi-classical Marcus theory, calling for better understanding and evaluation of carrier mobility. On the other hand, bandlike transport behavior has been observed for some ultra-pure and closely-packed organic single crystals. In this work, we identify the roles of quantum nuclear tunnelling and the charge delocalization effects, leading to a comprehensive computational approach to assess the carrier mobility of organic semiconductors. We present the first-principles evaluated mobility results for some representative organic transport materials at four levels ranging from semiclassical hopping to quantum nuclear enabled hopping and to quantum wavepacket diffusion, and eventually to complete bandlike descriptions. We provide a comprehensive tool to assess the carrier mobility in organic semiconductors based on such improved understanding.
近年来，有机半导体的实验载流子迁移率值迅速增加，远远超过了基于使用半经典马库斯理论计算的跳跃模型的理论极限，这就需要对载流子迁移率有更好的理解和评估。另一方面，在一些超纯且紧密堆积的有机单晶中观察到了类能带传输行为。在这项工作中，我们确定了量子核隧穿和电荷离域效应的作用，从而形成了一种全面的计算方法来评估有机半导体的载流子迁移率。我们给出了一些代表性有机传输材料在从半经典跳跃到量子核辅助跳跃、再到量子波包扩散，最终到完整类能带描述的四个层次上的第一性原理评估迁移率结果。基于这种改进的理解，我们提供了一个评估有机半导体载流子迁移率的综合工具。
