Efficient Radiative Pumping of Polaritons in a Strongly Coupled Microcavity by a Fluorescent Molecular Dye
Efficient Radiative Pumping of Polaritons in a Strongly Coupled Microcavity by a Fluorescent Molecular Dye
复制标题
DOI：
10.1002/adom.201600337
复制
发表时间：
2016-10-01
影响因子：
9
通讯作者：
Lidzey, David G.
中科院分区：
文献类型：
--
作者：
Grant, Richard T.;Michetti, Paolo;Lidzey, David G.
研究了一系列强耦合微腔的光学性质，其中荧光分子染料BODIPY-Br（溴取代硼-二吡咯-亚甲基）分散在透明介质基质中，每个微腔具有不同的激子-光子失谐量.利用温度相关的发射，时间分辨光谱，白光反射率，和荧光量子产率的测量，探讨了沿着较低的极化激元分支的极化激元的人口。发现腔荧光量子效率和极化激元态沿着下极化激元分支的分布都是激子-光子失谐量的函数。重要的是，它表明，在最负失谐腔，发射量子效率接近的控制（noncavity）膜。一个简单的拟合模型，这是基于直接辐射泵浦的极化激元状态沿着较低的极化激元分支，并使用它来获得一个很好的协议与测量的光致发光作为温度和激子光子失谐的函数，和定性协议与测量的光致发光量子效率。辐射泵浦机制表明，为了促进在含有分散分子染料的强耦合微腔中形成非平衡极化激元凝聚体，重要的是利用具有高荧光量子效率和快辐射速率的材料。
The optical properties of a series of strongly coupled microcavities containing the fluorescent molecular dye BODIPY-Br (bromine-substituted boron-dipyr-romethene) dispersed into a transparent dielectric matrix are explored, with each cavity having a different exciton-photon detuning. Using temperature dependent emission, time-resolved spectroscopy, white-light reflectivity, and measurements of fluorescence quantum yield, the population of polaritons is explored along the lower polariton branch. It is found that both the cavity fluorescence quantum efficiency and the distribution of polariton states along the lower polariton branch is a function of exciton-photon detuning. Importantly, it is shown that in the most negatively detuned cavities, the emission quantum efficiency approaches that of a control (noncavity) film. A simple fitting model is developed, which is based upon direct radiative pumping of polariton states along the lower polariton branch and used it to obtain an excellent agreement with measured photoluminescence as a function of temperature and exciton-photon detuning, and qualitative agreement with the measured photoluminescence quantum efficiency. The radiative pumping mechanism indicates that to facilitate the formation of a nonequilibrium polariton condensate in strongly-coupled microcavities containing dispersed molecular dyes, it is important to utilize materials having high fluorescent quantum efficiency and fast radiative rates.