Vibrationally Assisted Polariton-Relaxation Processes in Strongly Coupled Organic-Semiconductor Microcavities
Vibrationally Assisted Polariton-Relaxation Processes in Strongly Coupled Organic-Semiconductor Microcavities
复制标题
DOI：
10.1002/adfm.201100756
复制
发表时间：
2011-10-07
影响因子：
19
通讯作者：
Lidzey, David G.
中科院分区：
文献类型：
--
作者：
Coles, David M.;Michetti, Paolo;Lidzey, David G.
如果将具有近似于二能级系统的电子跃迁的半导体放置在光学腔内，则在受限光子和半导体激子之间可以发生强耦合。这种耦合可以导致形成光和物质的相干叠加的腔极化激元状态。如果腔中的材料是有机半导体，则已经预测Frenkel激子、极化激元和分子振动模式之间的相互作用将在定义系统的整体弛豫动力学方面具有深远的作用。在这里，使用依赖于温度的光谱上的微腔含有J-聚集的花青染料，它示出的光谱的局部振动模式（由拉曼散射识别）增强了人口的某些极化激子模式作为能量损失通道的激子，因为它们经历散射。我们的工作表明，同时控制腔的光学性质和分子染料的振动结构可以促进k = 0极化激元态的有效布居，由此可能发生激光和其他合作现象。
If a semiconductor with an electronic transition that approximates a two-level system is placed within an optical cavity, strong coupling can occur between the confined photons and the semiconductor excitons. This coupling can result in the formation of cavity polariton states that are a coherent superposition of light and matter. If the material in the cavity is an organic semiconductor, it has been predicted that interactions between Frenkel excitons, polaritons, and molecular vibrational modes will have a profound role in defining the overall relaxation dynamics of the system. Here, using temperature-dependent spectroscopy on a microcavity containing a J-aggregated cyanine dye, it is shown that a spectrum of localized vibrational modes (identified by Raman scattering) enhances the population of certain polaritonic modes by acting as an energy-loss channel to the excitons as they undergo scattering. Our work demonstrates that simultaneous control of the optical properties of a cavity and the vibrational structure of a molecular dye could promote the efficient population of k = 0 polariton states, from which lasing and other cooperative phenomena may occur.