Excellence in Research: Structure and Dynamics of Exciplexes in Thermally Activated Delayed Fluorescence

卓越研究：热激活延迟荧光中激基复合物的结构和动力学

• 批准号: 2200387
• 负责人: Seyhan Salman
• 金额: $ 32万
• 依托单位: Clark Atlanta University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2200387&HistoricalAwards=false
• 关键词: Excellence; Research; Structure; Dynamics; Exciplexes

In this project, jointly funded by the Office of Integrative Activities (OIA), the Chemical Structure, Dynamics, and Mechanisms-A (CSDM-A) program in the Division of Chemistry, and the Electronic and Photonic Materials (EPM) program in the Division of Materials Research, Seyhan Salman and her research group at Clark Atlanta University are using theoretical models and computational tools to investigate the electronic structure and optical properties of organic light-emitting diode (OLED) materials that exhibit thermally activated delayed fluorescence (TADF). The project seeks to significantly advance the understanding of excited-state complexes (exciplexes) that are responsible for TADF based on their electronic structures and optical properties, as well as the various transition processes associated with the excited complexes. Better understanding of the fundamental structure and dynamics of such species will help guide the development of efficient new materials for applications in optical and electronic devices, including OLEDs, solar cells, field-effect transistors, (bio)chemical sensors and storage devices. The project also provides students from groups that are underrepresented in science with a challenging research experience and professional training in computational materials chemistry that will help prepare them for the STEM (science, technology, engineering and mathematics) workforce.The main goal of this project is to elucidate the excited-state dynamics of thermally activated delayed fluorescence (TADF) in exciplex-based OLED materials. Such systems represent one of the most promising classes of materials for realizing highly efficient OLEDs using organic molecules and could lead to a significant reduction in fabrication costs associated with this technology. The electronic structure and properties of exciplexes are influenced by the intermolecular interactions in the exciplex state, which are markedly different than that in the ground state and are relatively weak, leading to various structural conformations. Further studies of exciplexes, including their electronic structures, properties, and dynamics of charge and energy transfer processes, are needed for their application in OLEDs. This project uses state-of-the-art computational approaches with the goal of quantifying microscopic parameters and establishing structure-property relationships in these materials. The research team uses an integrated approach combining all-atom molecular dynamics (AA-MD) simulations with density functional theory (DFT) calculations to study the effect of the solid matrix environment on the emissive properties of exciplexes. They are also examining the impact of energetic disorder (static and dynamic components) on the efficiency of radiative decay processes. The impacts of host-guest interactions and the dynamics of charge- and energy-transfer processes are also included in the modeling scheme in order to account for intersystem crossing and other radiative and non-radiative transitions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在该项目中，由综合活动办公室（OIA）共同资助，化学结构，动力学和机制-A（CSDM-A）在化学部门以及材料研究部的电子和光子材料（EPM）计划（EPM）计划，Seyhan Salman和她的Clark Atlanta University的seyhan Salman及其计算机工具的构成型和计算机工具 - （OLED）表现出热活化延迟荧光（TADF）的材料。该项目旨在显着促进对基于其电子结构和光学特性以及与激发复合物相关的各种过渡过程的TADF的激发状态复合物（Expiplex）的理解。更好地了解此类物种的基本结构和动力学将有助于指导在光学和电子设备中应用有效的新材料，包括OLED和电子设备，包括OLED，太阳能电池，现场效应晶体管，（BIO）化学传感器和存储设备。该项目还为来自科学人数不足的小组的学生提供了具有挑战性的研究经验和计算材料化学方面的专业培训，这将有助于为STEM（科学，技术，工程和数学）劳动力做好准备。这样的系统代表了使用有机分子实现高效OLED的最有希望的材料类别之一，并可能导致与该技术相关的制造成本大大降低。 Exoplexes的电子结构和特性受到离子间相互作用的影响，这些相互作用与基态下的分子间相互作用明显不同，并且相对较弱，从而导致各种结构构象。需要进一步研究动力学，包括其电子结构，特性以及电荷和能量传递过程的动力学，以使其在OLED中应用。该项目使用最先进的计算方法，目的是量化显微镜参数并在这些材料中建立结构 - 陶艺关系。研究团队使用一种集成方法，该方法将全原子分子动力学（AA-MD）与密度功能理论（DFT）计算相结合，以研究固体基质环境对ExpiplexEs发射特性的影响。他们还正在研究能量障碍（静态和动态成分）对辐射衰减过程效率的影响。建模方案还包括了主机 - 格斯特相互作用以及电荷和能量转移过程的动态的影响，以说明Intersystem Crossing和其他辐射性和非辐射性过渡的影响。这项奖项反映了NSF的法定任务，并通过使用该基金会的知识优点和广泛的影响来评估NSF的法定任务。

项目成果

Identifying the origin of delayed electroluminescence in a polariton organic light-emitting diode

• DOI: 10.1515/nanoph-2023-0587
• 发表时间: 2023-09
• 期刊: Nanophotonics
• 影响因子: 7.5
• 作者: A. Abdelmagid;Hassan A. Qureshi;Michael A. Papachatzakis;Olli Siltanen;Manish Kumar;Ajith Ashokan;Seyhan Salman;K. Luoma;Konstantinos S. Daskalakis