Collaborative Research: Excited-State Dynamics in Organic Charge-Transfer Compounds: An Experimental and Theoretical Study

合作研究：有机电荷转移化合物的激发态动力学：实验和理论研究

基本信息

批准号：
1708147
负责人：
Veaceslav Coropceanu
金额：
$ 28.92万
依托单位：
Georgia Tech Research Corporation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2020-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708147&HistoricalAwards=false
关键词：
Collaborative Research Excited State Dynamics

项目摘要

Non-technical description: This project is a study of crystals made up of carbon-based organic molecules that conduct electricity in a way similar to the behavior of the silicon that makes up computer chips. The project aims to develop a fuller understanding of how these organic materials respond to light, and how the flow of electricity through them is affected by the vibrations of the molecules. Experiments that measure light absorbed and emitted by the crystals are compared to calculations of the various energies of the electrons in the crystal. From these experiments and calculations it is now possible to determine how the vibrations of the molecules affect the electrons that are responsible for the flow of electricity, thus gaining fundamental understanding of the electronic properties of these materials. The findings of this project help determine the best materials to use to make more efficient and cheaper electronic devices such as displays for flat-screen TVs and other media, photosensors, and solar cells. Graduate students and undergraduates participating in the project are developing valuable skills in experimentation and computation while contributing to fulfilling a national and global societal need for more efficient and sustainable technology.Technical description: Organic semiconductors are of significant interest due to their potential for opto-electronic applications such as solar cells and photosensors. Charge transfer compounds, which are made of two or more different organic molecules in which one species acts as a donor of electric charge and the other as an acceptor, could provide new properties or improved performance to increase the range of application of organic semiconductors. The goals of this project are to elucidate the excited-state dynamics of selected charge transfer compounds and develop a deep understanding of electronic couplings and electron-phonon couplings in them. Charge transport and excited-state dynamical processes are critical to applications of these materials in opto-electronic devices, and depend on a subtle interplay between electronic and electron-phonon interactions. Transient absorption and fluorescence lifetime measurements, when interpreted in light of computational evaluation of the rates of various electron-transfer processes, allow the decay mode of excitons in these materials to be determined. Resonant Raman experiments are used to extract relaxation energies and transfer integrals. These experimental findings are interpreted in light of site energies, electron-phonon and electronic couplings computed using a variety of methods, including density functional theory calculations of large molecular clusters and those based on periodic boundary conditions, semi-empirical approaches, and tight-binding models, and molecular dynamics simulations. This strongly-coupled series of experimental investigations and theoretical modeling opens a large range of functionalities not manifest in monomolecular solids. The findings ultimately contribute to fulfilling a national and global societal need for more efficient and sustainable technology.

非技术描述：该项目是对由碳基有机分子组成的晶体的研究，这些晶体以类似于构成计算机芯片的硅的行为的方式进行电力。该项目旨在对这些有机材料如何响应光以及通过它们的电流流动如何受到分子振动的影响。将测量晶体吸收和发射的光的实验与晶体中电子各能量的计算进行了比较。从这些实验和计算中，现在可以确定分子的振动如何影响负责电流的电子，从而获得对这些材料电子特性的基本了解。该项目的发现有助于确定最佳的材料，以制造更高效，更便宜的电子设备，例如用于平面电视和其他媒体，光电传感器和太阳能电池的显示器。参与该项目的研究生和本科生正在发展实验和计算方面有价值的技能，同时促进满足国家和全球社会对更高效和可持续的技术的需求。技术描述：有机半导体具有重大兴趣，因为它们对诸如Solar Cells和Photosenors之类的选择性应用程序的潜力。电荷转移化合物由两个或更多不同的有机分子制成，其中一个物种充当电荷的供体，另一种物种可以提供新的特性或改善性能以增加有机半导体的应用范围。该项目的目标是阐明所选电荷转移化合物的激发状态动力学，并深入了解它们中的电子耦合和电子波耦合。电荷传输和激发状态动力学过程对于这些材料在光电设备中的应用至关重要，并且取决于电子和电子 - 光子相互作用之间的微妙相互作用。瞬态吸收和荧光寿命测量值根据对各种电子转移过程的速率进行计算评估进行解释时，可以确定这些材料中激子的衰减模式。共振拉曼实验用于提取松弛能和转移积分。这些实验发现是通过使用多种方法计算的位点能量，电子音波和电子耦合来解释的，包括大分子簇的密度功能理论计算以及基于周期性边界条件，半经验方法，半经验方法以及紧密结合模型以及分子动力学模拟的方法。这一强耦合的一系列实验研究和理论建模开放了许多在单分子固体中未表现出来的功能。这些发现最终有助于满足对更高效和可持续技术的国家和全球社会需求。

项目成果

期刊论文数量（4）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Design and Synthesis of Two-Dimensional Covalent Organic Frameworks with Four-Arm Cores: Prediction of Remarkable Ambipolar Charge-Transport Properties

DOI：
10.1039/c9mh00035f
发表时间：
2019-02
期刊：
Materials Horizons
影响因子：
13.3
作者：
Simil Thomas;Hong Li;Raghunath R. Dasari;Austin M. Evans;William R. Dichtel;S. Marder;V. Coropceanu
通讯作者：
Simil Thomas;Hong Li;Raghunath R. Dasari;Austin M. Evans;William R. Dichtel;S. Marder;V. Coropceanu

Assessing the nature of the charge-transfer electronic states in organic solar cells