Designing light-matter hybrid states for high-performance organic (opto)electronics

非技术描述：有机分子与光之间的相互作用可以形成混合光-物质状态（极化子）。这种状态具有令人着迷的光学和电子特性，从基础物理学和应用的角度来看都是令人感兴趣的。极化子的应用包括激光、传感器、光通信和信息处理设备等。在这个项目中，利用实验和计算相结合的方法来探索极化子的特性，目的是设计下一代有机光电材料和器件架构，利用极化子增强的光发射和/或电导率。该项目将基础物理与材料设计和设备技术相结合，从而为研究生和本科生提供独特的教育资源和基础设施，包括那些参与该项目的弱势群体。研究人员根据项目的结果和相关概念开发教育材料，并参与各种各样的推广活动，包括为各种受众进行的实验室演示，以及参与全校和系里的推广活动。技术描述：有机（光电）电子材料由于其低成本和可调特性而引起人们的兴趣，并已被证明具有广泛的应用范围。在有机微腔中应用强激子-光子耦合是取得显著进展的领域之一。尽管在有机材料的强激子-光子耦合方面有大量的理论和实验工作，但关于杂化光-物质（极化子）态的性质和性质仍有许多未解决的基本问题。解决其中的一些问题，并为最近的一些理论预测提供实验验证，例如暗极化子（具有独特光物理特性的混合态）的理论预测，是本研究的目标。特别是，系统地研究了混合光物质态的光物理性质及其在可溶液加工的功能化苯乙烯和蒽噻吩衍生物模型有机半导体中增强电荷输运的能力。为此，将光学和光致发光光谱的各种模式与载流子动力学测量和数值模拟相结合。该研究的最终目标是建立微腔和等离子体纳米结构衬底上的混合光物质态的性质和特性，并量化这些态在有机晶体材料中增强相干电荷输运的潜力。更具体地说，研究小组试图确定极化子的性质是如何随着有机半导体中激子态的性质、分子堆积和无序而演变的，并为通过相干杂化态增强高性能有机半导体中的载流子迁移率和光电流奠定基础。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Description: Interactions between organic molecules and light may enable formation of a hybrid light-matter state (polariton). Such state has fascinating optical and electronic properties which are of interest both from the fundamental physics and from the applications perspective. The applications of polaritons include lasers, sensors, devices enabling optical communications and information processing, and many others. In this project, properties of polaritons are explored using a combination of experimental and computational approaches with the goal of designing next-generation organic optoelectronic materials and device architectures that utilize enhanced light emission and/or conductivity enabled by polaritons. The project integrates fundamental physics with materials design and device technologies, thus providing unique educational resources and infrastructure for graduate and undergraduate students, including those from underrepresented groups, involved in this project. The investigators develop educational materials based on the results of the project and related concepts and participate in a broad variety of outreach activities ranging between lab-based demonstrations for various audiences and participation in university-wide and department-wide outreach initiatives.Technical Description: Organic (opto)electronic materials are of interest due to their low cost and tunable properties appropriate a broad range of applications has been demonstrated. One of the areas that has seen a dramatic progress is the applications relying on strong exciton-photon coupling in organic microcavities. In spite of considerable amount of theoretical and experimental work on strong exciton-photon coupling in organic materials, there is still a number of unresolved fundamental issues pertaining to the nature and properties of hybrid light-matter (polariton) states. Resolving some of these issues and providing experimental validation for some of the recent theoretical predictions, exemplified by that of a dark polariton (a hybrid state with unique photophysical characteristics), is the goal of the present research. In particular, a systematic investigation of photophysics of hybrid light-matter states and their ability to enhance charge transport in model organic semiconductors, chosen to be solution-processable functionalized acene and anthradithiophene derivatives, is carried out. For this, various modalities of optical and photoluminescence spectroscopy are combined with measurements of charge carrier dynamics and with numerical simulations. The ultimate goal of the research is to establish the nature and properties of hybrid light-matter states in microcavities and on plasmonic nanostructured substrates and to quantify the potential of such states to enhance coherent charge transport in organic crystalline materials. More specifically, the research team seeks to establish how the properties of polaritons evolve depending on the nature of excitonic states in the organic semiconductor, molecular packing and disorder, and to lay foundations for enhancing charge carrier mobility and photocurrent in high-performance organic semiconductors via coherent hybrid states.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.