Quantifying the number of chromophores and the kinetics of exciton diffusion in nanoparticles with picosecond time-resolved photon antibunching (psTRAB)

使用皮秒时间分辨光子反聚束 (psTRAB) 量化纳米粒子中的发色团数量和激子扩散动力学

• 批准号: 470075523
• 负责人: Professor Dr. Philip Tinnefeld
• 金额: --
• 依托单位: Institut für Experimentelle und Angewandte Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/470075523?language=en
• 关键词: Quantifying; number; chromophores; kinetics; exciton

The particle nature of light becomes most evident by studying the fluorescence of single quantum systems, such as organic chromophores or quantum dots. Provided that there is no biexcitonic species formed, not more than one single photon is emitted in one excitation cycle, i.e. photon antibunching appears in the photon statistics. In multichromophoric particles, such as light-harvesting complexes and conjugated polymers, the photon statistics hides important information regarding energy transfer and subsequent exciton annihilation processes but is impossible to interpret without further knowledge about the particles, e.g. the size or number of chromophores. However, energy transfer is a time-dependent process and therefore the signatures thereof must be hidden in the photon stream. We will employ and further develop our technique of picosecond time-resolved photon antibunching (psTRAB) to unravel such signatures and demonstrate on well-defined multichromophoric DNA-origami structures and well-defined multichromophoric molecules that energy transfer processes between multiple dye molecules can indeed be measured. In a second step, we will apply this technique to various poorly defined multichromophoric nanoparticles, such as single conjugated polymer chains and mesoscopic conjugated polymer aggregates with distinct electronic aggregation behaviour, e.g. H- and J-type aggregation, and with different sizes to unravel the nature and efficiency of energy transfer in this important class of materials. Finally, we also want to venture into the interesting class of monolayer transition metal dichalcogenides (TMDCs) and investigate the possibility of using psTRAB to study exciton-exciton annihilation in 2D materials. Single-molecule spectroscopy, or rather single-particle spectroscopy, is the obvious technique for this because both static and dynamic heterogeneities can be resolved.

通过研究单个量子系统（如有机发色团或量子点）的荧光，光的粒子性质变得最为明显。如果没有形成双激子种，则在一个激发周期内发射的光子不超过一个，即在光子统计中出现光子反聚束。在多发色粒子中，如光收集配合物和共轭聚合物，光子统计隐藏了关于能量转移和随后的激子湮灭过程的重要信息，但如果没有对粒子的进一步了解，例如发色团的大小或数量，就不可能解释。然而，能量传递是一个时间相关的过程，因此其特征必须隐藏在光子流中。我们将利用并进一步发展我们的皮秒时间分辨光子反束（psTRAB）技术来解开这些特征，并证明在定义良好的多色dna折纸结构和定义良好的多色分子上，多个染料分子之间的能量转移过程确实可以测量。在第二步中，我们将把这项技术应用于各种不明确的多色纳米颗粒，如单共轭聚合物链和具有不同电子聚集行为的介观共轭聚合物聚集体，例如H型和j型聚集，以及不同尺寸，以揭示这类重要材料中能量转移的性质和效率。最后，我们还想冒险进入有趣的单层过渡金属二硫化物（TMDCs）类别，并研究使用psTRAB研究二维材料中激子-激子湮灭的可能性。单分子光谱学，或者更确切地说是单粒子光谱学，是显而易见的技术，因为静态和动态异质性都可以被解决。