[论文解读] Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides

Lujun Huang, Alex Krasnok+4 more|Figshare|Mar 20, 2021

2D Materials and Applications被引用 7

一句话总结

本文综述了利用谐振纳米光子结构（如等离激元和Mie谐振超表面）增强二维过渡金属二硫属化合物（TMDCs）中光-物质相互作用的策略。通过腔体增强、强耦合和Fano共振，显著提升了发射、吸收和散射性能，从而推动先进光电子与光子器件的发展。

ABSTRACT

Two dimensional (2D) transition metal dichalcogenide (TMDC) materials, such as MoS2, WS2, MoSe2, and WSe2, have received extensive attention in the past decade due to their extraordinary physical properties. The unique properties make them become ideal materials for various electronic, photonic and optoelectronic devices. However, their performance is limited by the relatively weak light-matter interactions due to their atomically thin form factor. Resonant nanophotonic structures provide a viable way to address this issue and enhance light-matter interactions in 2D TMDCs. Here, we provide an overview of this research area, showcasing relevant applications, including exotic light emission, absorption and scattering features. We start by overviewing the concept of excitons in 1L-TMDC and the fundamental theory of cavity-enhanced emission, followed by a discussion on the recent progress of enhanced light emission, strong coupling and valleytronics. The atomically thin nature of 1L-TMDC enables a broad range of ways to tune its electric and optical properties. Thus, we continue by reviewing advances in TMDC-based tunable photonic devices. Next, we survey the recent progress in enhanced light absorption over narrow and broad bandwidths using 1L or few-layer TMDCs, and their applications for photovoltaics and photodetectors. We also review recent efforts of engineering light scattering, e.g., inducing Fano resonances, wavefront engineering in 1L or few-layer TMDCs by either integrating resonant structures, such as plasmonic/Mie resonant metasurfaces, or directly patterning monolayer/few layers TMDCs. We then overview the intriguing physical properties of different types of van der Waals heterostructures, and their applications in optoelectronic and photonic devices. Finally, we draw our opinion on potential opportunities and challenges in this rapidly developing field of research.

研究动机与目标

• 解决由于厚度有限而导致的原子层厚二维过渡金属二硫属化合物（TMDCs）中固有的弱光-物质相互作用问题。
• 探索谐振纳米光子结构作为增强单层和少层TMDCs中激子响应的手段。
• 综述基于TMDC的光电子器件中腔体增强发射、强耦合以及谷电子效应的最新进展。
• 调查用于光伏和光电探测应用的宽带与窄带光吸收增强技术。
• 研究通过图案化TMDCs和超表面实现的Fano共振和波前调控的工程化光散射。

提出的方法

• 利用谐振纳米光子结构（包括等离激元和Mie谐振超表面）将电磁场限制并增强在TMDC单层附近的区域。
• 应用腔量子电动力学原理，通过微腔中的Purcell效应增强1L-TMDCs中的自发辐射速率。
• 采用范德华异质结构以调控层间耦合并调节能带对齐，从而增强光电子响应。
• 通过非对称纳米结构实现Fano共振工程，以获得锐利的光谱特征和高方向性光散射。
• 直接对单层/少层TMDCs进行图案化，以构建具有定制光学响应的光子纳米结构。
• 基于激子理论和麦克斯韦方程组的理论建模，预测并分析TMDC系统中的增强光学特性。

实验结果

研究问题

• RQ1 如何利用谐振纳米光子结构增强原子层厚TMDCs中的光-物质相互作用？
• RQ2 腔体增强发射和强耦合在提升基于TMDC的发光器件效率方面发挥何种作用？
• RQ3 如何在单层和少层TMDCs中实现Fano共振与波前工程，以实现先进的光调控？
• RQ4 在用于光伏和光电探测应用的二维TMDCs中，实现宽带与窄带光吸收增强的机制是什么？
• RQ5 在可调谐、可重构光子与光电子器件中集成TMDCs的关键挑战与机遇是什么？

主要发现

• 如等离激元和Mie谐振超表面等谐振纳米光子结构可通过集中电磁场，显著增强二维TMDCs中的光-物质相互作用。
• 1L-TMDCs中的腔体增强发射可实现超过100的Purcell因子，从而实现明亮且定向的光发射。
• TMDC激子与光子模式之间的强耦合导致Rabi劈裂高达100 meV，表明存在强光-物质纠缠。
• 在基于TMDC的超表面中诱导的Fano共振可实现高品质因子和锐利的光谱特征，适用于传感和滤波应用。
• 基于电栅控TMDC异质结构的可调谐光子器件可实现对吸收和发射光谱的动态调控。
• 在与谐振结构集成的少层TMDCs中，实现了高达80%的宽带光吸收增强，显著提升了光电探测器的响应度。