QM/MM investigation of the degradation mechanism of the electron-transporting layer
QM/MM investigation of the degradation mechanism of the electron-transporting layer
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DOI：
10.1007/s00214-011-1020-y
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发表时间：
2011-08
影响因子：
1.7
通讯作者：
T. Asada;K. Ohta;T. Matsushita;S. Koseki
中科院分区：
文献类型：
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作者：
T. Asada;K. Ohta;T. Matsushita;S. Koseki
采用量子力学/分子力学（QM/MM）计算和分子动力学（MD）模拟，从理论上研究了非晶条件下电子传递层（ETL）中三（8-羟基喹啉酸盐）铝（Alq3）分子间的电荷转移机理。基于跳变模型和Marcus理论，对QM/MM动力学模拟得到的平衡结构的电子转移速率常数进行了估计。研究发现，ETL中（lif4）簇的配位显著降低了alq3分子中最低未占据分子轨道的能量。ETL中速率常数小，即电荷迁移率慢，被认为与（lif4）簇协调的alq3的低处离域未占据分子轨道有因果关系。结果表明，它们的相互作用对效率有相当大的影响，部分归因于有机发光二极管的ETL降解。
The mechanism of charge transfer among tris(8-hydroxyquinolinate)aluminum (Alq3) molecules in the electron-transporting layer (ETL) under amorphous conditions was theoretically investigated using both quantum mechanical/molecular mechanical (QM/MM) calculations and molecular dynamics (MD) simulations. The rate constant of the electron transfer was estimated for the equilibrated structure taken from the QM/MM MD simulations, based on the hopping model and Marcus theory. It was found that the coordination of a (LiF)4cluster in ETL drastically lowers the energy of the lowest unoccupied molecular orbital in the Alq3molecule. The small rate constant, namely the slow charge mobility, in ETL is believed to be causally related to the low-lying delocalized unoccupied molecular orbital of Alq3coordinated by the (LiF)4cluster. The results suggest that their interaction has a considerable influence on efficiency and is attributed in part to ETL degradation in organic light-emitting diodes.