Collaborative Research: Quasiparticle Transport in Organic Materials: Vibrational Dressing, Static Disorder, Nanoscale Confinement, and Quantum Effects

合作研究：有机材料中的准粒子输运：振动修整、静电无序、纳米级约束和量子效应

• 批准号: 0097210
• 负责人: Paul Parris
• 金额: $ 14.7万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0097210&HistoricalAwards=false
• 关键词: Collaborative; Research; Quasiparticle; Transport; Organic

0097210ParrisThis is a Collaborative Research Project between the University of New Mexico and the University of Missouri at Rolla. The research performed is theoretical, employ analytic and computer methods, and deals with fundamental issues of quasiparticle transport in organic materials on the one hand, and applications to technologically important systems and devices on the other hand. Among the fundamental issues it addresses are dynamic disorder, static disorder, intense applied fields, carrier-carrier interactions, and quantum effects arising from variation in the characteristic size of the systems under study.Breaking the translational invariance by strong interactions of quasiparticles, such as electrons, with vibrations and other oscillatory motions of molecules, constitutes dynamic disorder. Some of the issues to be addressed are very new, while others are longstanding but unresolved: What is the nature of the fundamental carriers of charge and enegy in organic solids? To what extent are they localized or extended in space, free or associated with distortions around them (polaronic), coherent or incoherent in their motion? What new effects on dynamics may be expected as a result of system size variation from the mesoscale to the nanoscale? Theoretical investigations to be performed will seek to determine conditions under which transport is normal or (and to what quantitative extent) anomalous in the sense of dispersive, so that application of ordinary equilibrium statistical mechanics may not mislead quantitative assessment of experiment. Investigations will also address the possibility of formation, as well as the effects on experiments, of composite particles: electron-photon (e.g., polaron), exciton-phonon (e.g., excimer), phonon-phonon (e.g., vibron), and exciton-photon (e.g., polariton) in limits in which the characteristic motion times of the constituent elements are disparate.Static disorder, both spatial and energetic, arises in organic materials from random molecular packings, chemical impurities, charge-dipole interactions, and orientational and spatial inhomogeneities. Such mechanisms can, and often do, lead to static disorder chacterized by substantial spatial correlations. Research will focus on the sources and possible control of such correlations and their effects on quasiparticle transport. Studies will be performed of the interplay and competition that occurs between correlated and uncorrelated sources of disorder, and a variety of effects, such as rate inversion in polaronic systems, that can arise from a combination of high fields, the polaronic nature of charge, and disorder.On the basis of insights gained through this work on fundamental aspects of quantum transport of quasiparticles, the research will focus on a number of practical device issues and phenomena including the screening of charge-dipole interactions, the mutual interaction of charges during injection, interfacial effects in organic light-emitting diodes and field effect transistors, recombination, and photogeneration. It will also address special device features such as geometrical constraints, reduced dimensionality, reduced phase space, and particularly the nanoscale (more appropriately the meso-micro-nano-scale) transition.%%% This is a Collaborative Research Project between the University of New Mexico and the University of Missouri at Rolla. The research performed is theoretical, employ analytic and computer methods, and deals with fundamental issues of quasiparticle transport in organic materials on the one hand, and applications to technologically important systems and devices on the other hand. ***

0097210Parris这是新墨西哥大学和密苏里大学罗拉分校之间的合作研究项目。 所进行的研究是理论性的，采用分析和计算机方法，一方面处理有机材料中准粒子输运的基本问题，另一方面处理在技术上重要的系统和设备中的应用。 它解决的基本问题包括动态无序、静态无序、强应用场、载流子相互作用以及所研究系统的特征尺寸变化引起的量子效应。准粒子（例如电子）与分子的振动和其他振荡运动的强相互作用打破了平移不变性，构成了动态无序。 一些需要解决的问题是非常新的，而另一些则是长期存在但尚未解决的问题：有机固体中电荷和能量的基本载体的本质是什么？ 它们在多大程度上在空间中定位或延伸、自由或与周围的扭曲相关（极化）、运动相干或不相干？ 系统尺寸从介观尺度到纳米尺度的变化可能会对动力学产生哪些新的影响？ 要进行的理论研究将寻求确定在色散意义上传输正常或（以及在定量程度上）异常的条件，以便普通平衡统计力学的应用不会误导实验的定量评估。 研究还将解决复合粒子形成的可能性以及对实验的影响：电子-光子（例如，极化子）、激子-声子（例如，准分子）、声子-声子（例如，振动子）和激子-光子（例如，极化子）在组成元素的特征运动时间不同的限制下。静态 有机材料中的空间和能量无序是由随机分子堆积、化学杂质、电荷偶极相互作用以及取向和空间不均匀性引起的。 这种机制可以而且经常确实导致以大量空间相关性为特征的静态无序。 研究将集中于这种相关性的来源和可能的控制及其对准粒子输运的影响。 将研究相关和不相关的无序源之间发生的相互作用和竞争，以及各种效应，例如极化系统中的速率反转，这些效应可能由高场、电荷的极化性质和无序的组合产生。基于通过这项关于准粒子量子输运基本方面的工作获得的见解，该研究将重点关注许多实际设备问题和现象，包括筛选 电荷偶极子相互作用、注入过程中电荷的相互作用、有机发光二极管和场效应晶体管的界面效应、复合和光生。 它还将解决特殊的器件特征，例如几何约束、减小的维度、减小的相空间，特别是纳米级（更准确地说是介观-微米-纳米级）转变。%%%这是新墨西哥大学和密苏里大学罗拉分校之间的合作研究项目。 所进行的研究是理论性的，采用分析和计算机方法，一方面处理有机材料中准粒子输运的基本问题，另一方面处理在技术上重要的系统和设备中的应用。 ***