Wang Chih-Feng, El-Khoury Patrick Z
Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States.
J Phys Chem A. 2022 Sep 1;126(34):5832-5836. doi: 10.1021/acs.jpca.2c04120. Epub 2022 Aug 17.
Low-dimensional transition-metal dichalcogenides (TMDs) continue to comprise a subject of intense research because of their unique optical and electronic properties that may be harnessed in modern devices. Intense photoluminescence (PL) from few-/monolayer TMDs rendered PL-based micro- and nanospectroscopic characterization ideal in the quest to understand the correlation between structure and function in these materials. Nonlinear optical methods are by comparison far less utilized for this purpose. In this work, we describe an approach based on electronically resonant four-wave-mixing that allows spatio-spectral characterization of excitons in monolayer WSe. Due to the coherent nature of the response that we exploit to trace exciton resonances, and recent demonstrations of electronic four-wave-mixing-based nanoimaging and nanospectroscopy, our present work is an important step toward characterizing TMDs on the nano-femto scale using light.
低维过渡金属二硫属化物（TMDs）因其独特的光学和电学性质而一直是深入研究的对象，这些性质可应用于现代器件中。少数/单层TMDs发出的强烈光致发光（PL）使得基于PL的微纳光谱表征成为理解这些材料结构与功能之间相关性的理想方法。相比之下，非线性光学方法在这方面的应用要少得多。在这项工作中，我们描述了一种基于电子共振四波混频的方法，该方法能够对单层WSe中的激子进行空间光谱表征。由于我们利用的响应具有相干性质来追踪激子共振，以及最近基于电子四波混频的纳米成像和纳米光谱的演示，我们目前的工作是朝着使用光在纳秒至飞秒尺度上表征TMDs迈出的重要一步。
