标题： 室温下胶体J聚集片中的表面激子极化子 显示英文标题

标题： Room-Temperature Surface Exciton Polaritons in Colloidal J-Aggregate Flakes

摘要： J-聚集体由于其激子特性以及在室温下支持表面激子极化子的能力，是纳米光子应用中有前途的有机材料，为纳米尺度的光操控提供了强大的平台。 尽管由J-聚集体组成的薄膜已展示了这些优势，但胶体J-聚集体纳米颗粒仍研究不足。 在此，我们报告了通过氰胺分子（TDBC）和带相反电荷的聚电解质（聚二烯丙基二甲基氯化铵，PDDA）的静电相互作用合成胶体J-聚集体薄片。 这些薄片表现出胶体稳定性，在有利于其单体状态的溶剂中仍能保持J-聚集体构型。 对胶体J-聚集体薄片的表征显示它们能够在室温下支持表面激子极化子。 通过在单粒子水平上观察到接近激子共振的角无关Reststrahlen带，进一步证实了这一点。 此外，胶体薄片表现出强烈的散射成分，拓宽了消光带并使荧光发射发生红移，表明胶体结构影响了光学响应。 这些发现引入了一种通用的胶体系统，用于构建针对先进光子应用的激子纳米结构。 显示英文摘要

摘要： J-aggregates are promising organic materials for nanophotonic applications due to their excitonic properties and ability to support surface exciton polaritons at room temperature, providing a robust platform for nanoscale light manipulation. While thin films composed of J-aggregates have demonstrated these advantages, colloidal J-aggregate nanoparticles remain underexplored. Herein, we report the synthesis of colloidal J-aggregate flakes by electrostatic interaction of cyanine molecules (TDBC) and oppositely charged polyelectrolytes (polydiallyldimethylammonium chloride, PDDA). These flakes exhibit colloidal stability maintaining the J-aggregate conformation even in solvents that favoured their monomeric state. The characterization of the colloidal J-aggregate flakes reveals their capability to support surface exciton polaritons at room temperature. This was further confirmed at single-particle level by observing an angular-independent Reststrahlen band near the excitonic resonance. In addition, the colloidal flakes exhibit a strong scattering component that broadens the extinction band and redshifts the photoluminescence, indicating that the colloidal architecture influences the optical response. These findings introduce a versatile colloidal system for constructing excitonic nanostructures tailored for advanced photonic applications.