Department of Materials and Interfaces, Faculty of Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
Phys Chem Chem Phys. 2018 Aug 15;20(32):20812-20820. doi: 10.1039/c8cp02245c.
Transition metal dichalcogenide materials have recently been shown to exhibit a variety of intriguing optical and electronic phenomena. Focusing on the optical properties of semiconducting WS2 nanotubes, we show here that these nanostructures exhibit strong light-matter interaction and form exciton-polaritons. Namely, these nanotubes act as quasi 1-D polaritonic nano-systems and sustain both excitonic features and cavity modes in the visible-near infrared range. This ability to confine light to subwavelength dimensions under ambient conditions is induced by the high refractive index of tungsten disulfide. Using "finite-difference time-domain" (FDTD) simulations we investigate the interactions between the excitons and the cavity mode and their effect on the extinction spectrum of these nanostructures. The results of FDTD simulations agree well with the experimental findings as well as with a phenomenological coupled oscillator model which suggests a high Rabi splitting of ∼280 meV. These findings open up possibilities for developing new concepts in nanotube-based photonic devices.
过渡金属二卤化物材料最近被证明具有多种有趣的光学和电子现象。本文聚焦于半导体 WS2 纳米管的光学性质，我们展示了这些纳米结构表现出强烈的光物质相互作用，并形成激子极化激元。具体来说，这些纳米管作为准 1-D 极化激元纳米系统，在可见光近红外范围内同时支持激子特征和腔模。在环境条件下将光限制在亚波长尺寸的能力是由二硫化钨的高折射率引起的。我们使用“时域有限差分”（FDTD）模拟来研究激子和腔模之间的相互作用及其对这些纳米结构消光谱的影响。FDTD 模拟的结果与实验结果以及一个唯象的耦合振荡器模型一致，该模型表明约 280 meV 的高拉比分裂。这些发现为基于纳米管的光子器件的新概念的发展开辟了可能性。
