Department of Materials, University of Oxford , Oxford OX1 3PH, United Kingdom.
Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, IT-16163 Genova, Italy.
Nano Lett. 2016 Nov 9;16(11):7137-7141. doi: 10.1021/acs.nanolett.6b03433. Epub 2016 Oct 27.
Colloidal semiconductor nanoplatelets exhibit quantum size effects due to their thickness of only a few monolayers, together with strong optical band-edge transitions facilitated by large lateral extensions. In this article, we demonstrate room temperature strong coupling of the light and heavy hole exciton transitions of CdSe nanoplatelets with the photonic modes of an open planar microcavity. Vacuum Rabi splittings of 66 ± 1 meV and 58 ± 1 meV are observed for the heavy and light hole excitons, respectively, together with a polariton-mediated hybridization of both transitions. By measuring the concentration of platelets in the film, we compute the transition dipole moment of a nanoplatelet exciton to be μ = (575 ± 110) D. The large oscillator strength and fluorescence quantum yield of semiconductor nanoplatelets provide a perspective toward novel photonic devices by combining polaritonic and spinoptronic effects.
胶体半导体纳米板的厚度只有几个单原子层，因此表现出量子尺寸效应，同时大的横向扩展也促进了强光学带边跃迁。在本文中，我们展示了 CdSe 纳米板的光和重空穴激子跃迁与开放式平面微腔的光子模式在室温下的强耦合。观察到重空穴和轻空穴激子的真空拉比分裂分别为 66 ± 1 meV 和 58 ± 1 meV，同时还观察到两种跃迁的极化子介导的杂化。通过测量薄膜中纳米板的浓度，我们计算出纳米板激子的跃迁偶极矩为 μ = (575 ± 110) D。半导体纳米板的大振子强度和荧光量子产率为结合极化激元和自旋光电子效应的新型光子器件提供了前景。
