论文标题
在无序有机半导体中的离域化增强激子传输的机理
Mechanism of delocalisation-enhanced exciton transport in disordered organic semiconductors
论文作者
论文摘要
大型激子扩散长度通常可以改善有机半导体设备的性能，因为它们使能量在激子寿命期间可以更远地运输。然而，尚不完全了解无序有机材料中激子运动的物理学，并且在无序有机半导体中对量子力学分离式激子的运输进行建模是计算挑战。在这里，我们描述了有机半导体中的三维激子传输的第一个模型，包括在内的有机半导体中，包括离域化，混乱和偏振子形成。我们发现，离域化可以大大增加激子的运输。例如，在每个方向上少于两个分子的定位可以使激子扩散系数增加一个数量级。增强的机制是双重的：DELOCALISATION使激子既可以在每个跳跃中更频繁，更进一步跳跃。我们还量化了瞬时离地化的影响（激子高度分离式的短暂时期），并表明它在很大程度上取决于疾病和过渡偶极矩。
Large exciton diffusion lengths generally improve the performance of organic semiconductor devices, since they enable energy to be transported farther during the exciton lifetime. However, the physics of exciton motion in disordered organic materials is not fully understood, and modelling the transport of quantum-mechanically delocalised excitons in disordered organic semiconductors is a computational challenge. Here, we describe delocalised kinetic Monte Carlo (dKMC), the first model of three-dimensional exciton transport in organic semiconductors that includes delocalisation, disorder, and polaron formation. We find that delocalisation can dramatically increase exciton transport; for example, delocalisation across less than two molecules in each direction can increase the exciton diffusion coefficient by over an order of magnitude. The mechanism for the enhancement is twofold: delocalisation enables excitons both to hop more frequently and further in each hop. We also quantify the effect of transient delocalisation (short-lived periods where excitons become highly delocalised), and show it depends strongly on the disorder and the transition dipole moments.
