Imaging the polariton relaxation bottleneck in strongly coupled organic semiconductor microcavities
Imaging the polariton relaxation bottleneck in strongly coupled organic semiconductor microcavities
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DOI：
10.1103/physrevb.88.121303
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发表时间：
2013-09-30
影响因子：
3.7
通讯作者：
Lagoudakis, Pavlos G.
中科院分区：
文献类型：
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作者：
Coles, David M.;Grant, Richard T.;Lagoudakis, Pavlos G.
我们使用角分辨光致发光激发光谱来探测两个不同强耦合 J 聚集体有机半导体微腔的下极化子分支 (LPB) 上朝向最低状态 (k(断裂垂直条断裂垂直条) = 0) 的能量弛豫。我们发现沿上极化子分支（UPB）的状态能够进行有效的弛豫，以填充 LPB 上 k（虚线垂直条）= 0 附近的状态；通过 UPB 极化子快速弛豫到激子库而发生的过程。相反，光子分数 >0.5 的 LPB 态显然无法进一步弛豫至 k（破直条破直条）= 0，从而构成有效的弛豫瓶颈。
We use angular-resolved photoluminescence excitation spectroscopy to probe energy relaxation towards the lowest lying states (k(broken vertical bar broken vertical bar) = 0) on the lower polariton branch (LPB) of two different strong-coupled J -aggregate organic semiconductor microcavities. We find that states along the upper polariton branch (UPB) are able to undergo efficient relaxation to populate states around k(broken vertical bar broken vertical bar) = 0 on the LPB; a process that occurs through the rapid relaxation of UPB polaritons to the exciton reservoir. In contrast, LPB states having a photon fraction >0.5 are not apparently able to undergo further relaxation towards k(broken vertical bar broken vertical bar) = 0, constituting an effective relaxation bottleneck.