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: 0097204
• 负责人: V. Kenkre
• 金额: $ 36.6万
• 依托单位: University of New Mexico
• 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 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0097204&HistoricalAwards=false
• 关键词: Collaborative; Research; Quasiparticle; Transport; Organic

0097204KenkreThis 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. ***

0097204 KenkreThis是新墨西哥州大学和密苏里州罗拉大学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，一方面涉及有机材料中准粒子输运的基本问题，另一方面涉及技术上重要的系统和设备的应用。 它涉及的基本问题包括动态无序、静态无序、强外加场、载流子-载流子相互作用以及所研究系统特征尺寸变化引起的量子效应。通过准粒子（如电子）与分子的振动和其他振荡运动的强相互作用打破平移不变性，构成动态无序。 一些需要解决的问题是非常新的，而另一些问题是长期存在但尚未解决的：有机固体中电荷和能量的基本载体的性质是什么？ 在多大程度上，它们在空间中是局部化的或延伸的，是自由的或与周围的扭曲有关（极化），在运动中是连贯的还是不连贯的？ 从中尺度到纳米尺度的系统尺寸变化会对动力学产生什么新的影响？ 要进行的理论研究将寻求确定条件下的传输是正常的或（以及到什么定量程度）反常的意义上的色散，使普通平衡统计力学的应用可能不会误导定量评估的实验。 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，受激准分子），声子-声子（例如，振动子），和激子-光子（例如，在有机材料中，由于随机分子堆积、化学杂质、电荷-偶极相互作用以及取向和空间不均匀性，产生空间和能量的静态无序。 这种机制可以，而且经常会导致静态无序，其特征是大量的空间相关性。 研究将集中在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的相互作用和竞争，以及各种效应，如极化系统中的速率反转，这可能是由高场、电荷的极化性质和无序的组合引起的。研究将集中在一些实际的器件问题和现象，包括电荷-偶极相互作用的屏蔽，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中的界面效应，复合和光生。 它还将解决特殊的器件特征，如几何约束，减少维度，减少相空间，特别是纳米尺度（更合适的是介-微-纳米尺度）过渡。这是新墨西哥州大学和位于罗拉的密苏里州大学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，一方面涉及有机材料中准粒子输运的基本问题，另一方面涉及技术上重要的系统和设备的应用。***