Theory and simulations of electronic processes in organic semiconductors

本计画系关于有机半导体系统中电荷与能量转移过程之理论与数值模拟。两个主要的项目组成部分集中在特定的核运动的作用和“模式投影”技术，允许减少一个高维量子动力学计算只涉及几个特定的“集体”模式。我们的目标是了解这种集体模式如何在光捕获系统和电荷转移系统中发挥作用。实际上，这些模式提供了对“反应坐标”的严格和分子水平的描述。“第三个组成部分涉及预测有机分子晶体和自组装有机半导体聚合物系统中激子极化激元态的性质。特别感兴趣的是在这些系统中的极化激元玻色凝聚态的可能性。这种凝聚体已经在GaAs微腔中观察到，但到目前为止，没有在有机microcavities.“模式投影”技术可以应用于广泛的情况下超越电子-声子系统，因此，提供了一个途径，在电子结构理论或电子输运理论的有效算法。在该项目中解决的系统是感兴趣的分子电子器件。极化激元BEC的研究虽然有一定的风险，但有相当大的希望产生广泛的影响，因为迄今为止还没有在有机微腔中观察到这种状态。在这些系统中的理论和模拟提供了非常需要的指导，在这个方向上的实验努力。当然，最广泛的影响是参与该项目的博士生和博士后研究人员的培训。该奖项由化学部的理论模型和计算方法计划资助。

This project concerns theoretical and numerical simulations of charge and energy transfer processes in organic semiconducting systems. Two major project components are focused upon the role of specific nuclear motions and a "mode projection" technique that allows to reduce a high-dimensional quantum dynamics calculation to one involving only a few specific "collective" modes. The goal is to understand how such collective modes come into play in light-harvesting systems and charge-transfer systems. In effect, these modes provide a rigorous and molecular level description of the "reaction coordinate." A third component concerns predicting the properties of exciton polariton states in organic molecular crystals and self-assembled organic semiconducting polymer systems. Of particular interest is the possibility of polariton Bose condensate states in these systems. Such condensates have been observed in GaAs microcavities but, thus far, not in organic microcavities.The "mode projection" technique can be applied in a wide range of cases beyond electron-phonon systems and, thus, offer an avenue for efficient algorithms in electronic structure theory or electronic transport theory. The systems addressed in the project are of interest for molecular electronic devices. The work on polariton BEC, while certainly risky, holds considerable promise for broad impact since such states have not been observed to date in organic semicondicting microcavities. The theory and simulations in these systems provide much needed guidance for experimental efforts in this direction. Certainly, the broadest impact is in the training of PhD students and postdoctoral researchers involved in this project. This award is funded by the Theory Models and Computational Methods program of the Chemistry Division.