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Electron dynamics of ultrafast energytransfer processes among quantum dots induced by long range electron correlation

长程电子关联引起的量子点间超快能量转移过程的电子动力学

基本信息

批准号：
242916180
负责人：
Professorin Dr. Annika Bande
金额：
--
依托单位：
Institut für Anorganische Chemie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2016-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/242916180?language=en
关键词：
Electron dynamics ultrafast energytransfer processes

项目摘要

Since a couple of years ultrafast energy transfer processes in clusters of atoms and molecules mediated by long-range electron correlation came into the focus of theoreticians and experimentalists. As a first process of such kind the interatomic Coulombic decay (ICD) was discovered, in which an electronically excited molecular cation relaxes into its ground state, while a neighboring molecule is ionized. Since then many variants of ICD were investigated in classical atomic and molecular systems. With a publication on the ICD process in quantum dots (QDs) in 2011 I started to establish the research on the aforementioned energy transfer processes for these technologically relevant semiconductor materials. In the novel methodology, on which also this project is based, highly correlated electron dynamics calculations are performed in model potentials for QDs according to the effective mass approximation (EMA). Due to the model potentials the results have a high degree of generality for different sorts of QDs. I further distinguish myself by using electron dynamics for calculations on a long-distance energy transfer processes as ICD. To do so I use an antisymmetric modification of the highly correlated multi-configuration time-dependent Hartree- (MCTDH) method that offers detailed knowledge of the wave function defined in the complete configuration space including the continuum. It furthermore allows for the natural adoption of optical pulses and scattering electrons. Therefore the whole procedure is optimal for the prediction of ICD and related phenomena in QDs.In this project I seek to extend the existing portfolio of methods in such a way that it becomes possible to make quick, flexible and binding predictions on electron and energy transfer processes in experimentally feasible arrays of various kinds of QDs. For this purpose the model will be combined with a dynamical treatment of phonons and excitons and furthermore generalized to the whole variety of realistic QD geometries. Electric fields of different form and strength for the optical control of energy transfer processes will be tested. The number of correlated electrons in the QDs will successively increase, requiring a transition from MCTDH to more efficient, presumably Gaussian-based methods for electron dynamics. With that the corner stone for a general electron dynamical treatment of ultrafast, long-range electron and energy transfer processes in realistic arrays of QDs - and moreover atoms and molecules - is placed. The expected results will furthermore serve to motivate technological use of the processes, i.e. the interatomic Coulombic electron capture (ICEC) for the generation of slow electrons and ICD for infrared photodetectors.

近几年来，原子团簇和分子团簇中由长程电子关联介导的超快能量传递过程成为理论和实验工作者关注的焦点。作为这种类型的第一个过程，发现了原子间库仑衰变（ICD），其中电子激发的分子阳离子弛豫到其基态，而邻近的分子被电离。从那时起，在经典的原子和分子系统中研究了ICD的许多变体。随着2011年关于量子点（QD）中ICD过程的出版物，我开始对这些技术相关的半导体材料的上述能量转移过程进行研究。在新的方法，这也是这个项目的基础上，高度相关的电子动力学计算进行量子点模型电位根据有效质量近似（EMA）。由于模型势的原因，结果对于不同类型的量子点具有高度的通用性。我进一步区分自己通过使用电子动力学的计算上的一个长距离的能量转移过程的ICD。要做到这一点，我使用反对称修改的高度相关的多配置时间相关的Hartree-（MCTDH）方法，提供详细的知识，定义在完整的配置空间，包括连续波函数。它还允许自然采用光脉冲和散射电子。因此，整个过程是最佳的预测ICD和相关现象在QDs.In这个项目中，我试图扩展现有的组合的方法，这样一种方式，它成为可能，使快速，灵活和约束力的预测电子和能量转移过程中的实验可行的各种量子点阵列。为此，该模型将结合声子和激子的动力学处理，并进一步推广到各种现实的量子点几何形状。将测试用于能量转移过程的光学控制的不同形式和强度的电场。量子点中相关电子的数量将连续增加，需要从MCTDH过渡到更有效的，可能是基于高斯的电子动力学方法。有了这个基石，超快，远程电子和能量转移过程中的量子点-而且原子和分子的现实阵列的一般电子动力学治疗被放置。预期的结果将进一步促进这些过程的技术应用，即用于产生慢电子的原子间库仑电子捕获和用于红外光电探测器的ICD。