DMREF: SusChEM: Simulation-Based Predictive Design of All-Organic Phosphorescent Light-Emitting Molecular Materials

DMREF：SusChEM：基于模拟的全有机磷光发光分子材料的预测设计

• 批准号: 1435965
• 负责人: John Kieffer
• 金额: $ 99.78万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435965&HistoricalAwards=false
• 关键词: DMREF; SusChEM; Simulation; Based; Predictive

DMREF: SUSCHEM: SIMULATION-BASED PREDICTIVE DESIGN OF ALL-ORGANIC PHOSPHORESCENT LIGHT-EMITTING MOLECULAR MATERIALSNon-technical Description: Organic light emitting diodes (OLED) exhibit remarkable energy efficiency in applications ranging from urban lighting to large-screen display panels. Current technologies are based on phosphorescent materials that contain organo-metallic compounds, which involve heavy-metal ions. These are expensive to procure, present limitations with regard to device longevity, and in some cases are considered environmentally unsafe or even toxic. The goal of this research is to eliminate the need for heavy-metal ions by developing a fundamentally new class of all-organic phosphorescent molecules. The principal task is to design molecules in which the juxtaposition of electronic orbitals promotes the processes underlying phosphorescence while at the same time the chemical bonding patterns provide the structural rigidity needed to minimize the non-radiative decay of electronic excitations. To this end an integrative computational-experimental approach is employed, in which molecular simulations, chemical synthesis, and materials characterization are combined in a synergistic and iterative sequence. The expected outcomes of this project are novel environmentally benign phosphorescent materials that are based on sustainable chemistries and that are immediately deployable for lighting applications. The new insights into the functional response of molecular materials gained while perfecting metal-free OLED benefits organic electronics in general, and advance technologies such as photovoltaics, sensors, and displays. Finally, software toolkits, data management utilities, and workflows for simulation-based predictive materials design are established as a new paradigm for materials development.Technical Description: The efficiency of phosphorescent materials is based on the ability to emit not only from singlet but also triplet excited states, which are populated as a result of spin-orbit coupling. The strength of this coupling is attributed to the presence of heavy-metal ions in organo-metallic compounds. However, organo-metallics are accompanied by significant challenges: besides the high cost of precious metals, dislocated metal ions in the emitting layer may trap charge, which jeopardizes device longevity. By serendipity, the co-PI demonstrated metal-free organic phosphors with unprecedented high solid-state phosphorescent quantum yield of up to 68% at ambient conditions. The current research aims to further develop this fundamentally new, environmentally benign, and chemically sustainable class of all-organic phosphorescent molecules with improved performance characteristics by employing an integrated computational-experimental approach. Specific objectives are to (i) eliminate the heavy metal ions form the emitting molecules with the aim to lower materials cost and obtainability, improve ease of fabrication, and prolong device lifetime and dependability; (ii) deconvolute the dual roles of halogen bonding, i.e., to promote spin-orbit coupling and suppress vibrational energy dissipation, and supplant the intermolecular secondary bonding-induced phosphorescence enhancement mechanism with intramolecular analogs; (iii) optimize the molecular architectures of both the emitting and host species so as to minimize vibration-mediated non-radiative decay of excited states through stiffening of intramolecular bonding patterns, stabilization of emitters by host molecules designed to suppress detrimental vibrations within effectively packed geometries, and crystallization of emitters within nano-confinement. To this end, concept emitter and host molecules are constructed and their structure and electronic properties, e.g., excited state energies, singlet-triplet transition rates, charge mobilities, etc., predicted using first-principles calculations. Structural models are generated using shape packing algorithms and molecular simulations, and possible crystal structures are predicted. Best candidate molecules are synthesized, characterized, and their emissive and vibrational properties measured.

DMREF：SUSCHEM：基于模拟的全有机磷光灯发光分子材料的预测设计NON-TECHNICAL描述：有机光发射二极管（OLED）在从城市照明到大型显示器面板的应用中表现出显着的能量效率。 当前的技术基于含有有机金属化合物的磷光材料，涉及重金属离子。这些是昂贵的，在设备寿命方面的当前限制，在某些情况下被认为是环境不安全甚至有毒的。 这项研究的目的是通过开发一类新的全有机磷光分子来消除对重金属离子的需求。 主要任务是设计分子，在该分子中，电子轨道的并置促进了磷光下的过程，而化学键合模式则提供了最小化电子激发的非辐射衰减所需的结构刚度。 为此，采用了一种综合计算实验方法，其中分子模拟，化学合成和材料表征与协同和迭代序列合并。 该项目的预期结果是基于可持续化学的新型环境良性磷光材料，可立即用于照明应用。 对获得的分子材料的功能响应的新见解，同时完善无金属OLED会使有机电子总体上受益，以及诸如光伏，传感器和显示器等高级技术。 最后，软件工具包，数据管理实用程序和基于模拟的基于模拟的预测材料设计的工作流是用于材料开发的新范式。技术描述：磷光材料的效率基于不仅从Singlet发出的能力，还可以激发状态，由于自旋轨道耦合而被填充。这种耦合的强度归因于有机金属化合物中的重金属离子的存在。但是，有机金属层伴随着重大挑战：除了贵金属的高成本外，发射层中的脱位金属离子可能会捕获电荷，这会危害器件的寿命。通过偶然性，CO-PI在环境条件下表现出具有前所未有的高固态磷光量子产率高达68％的无金属有机磷。当前的研究旨在进一步开发这种从根本上开发出这种新的，环境良性和化学可持续的全有机磷光分子，并采用综合计算实验性方法，具有改善的性能特征。特定的目标是（i）消除重金属离子形成发射分子的目的，目的是降低材料成本和可获得性，提高制造的易度性以及延长设备寿命和可靠性； （ii）否定卤素键合的双重作用，即促进自旋轨道耦合并抑制振动能量耗散，并取代了分子内分子类似物的分子间二次键合诱导的磷光度增强机制； （iii）优化发射物种和宿主物种的分子体系结构，以最大程度地减少激发态的振动介导的非辐射性衰变，通过僵硬的分子内结合模式，旨在通过旨在抑制有效堆积有害堆积的质量图的振动的宿主分子稳定发射器，并在纳米填充中的发射器结晶。为此，构建了概念发射极和宿主分子，其结构和电子特性，例如激发态能量，单线 - 三曲线过渡速率，电荷迁移率等，使用第一原理计算预测。使用形状堆积算法和分子模拟生成结构模型，并预测可能的晶体结构。最佳候选分子是合成，表征的，并测量其发射和振动特性。