AI 中文总结
研究单层MoS2与金纳米立方体阵列耦合时的激子增强，通过改变纳米立方体边长及间隔层材料和厚度，实现多参数系统调谐，增强光致发光，确立其为可调谐等离子体平台，可用于增强激子载流子产生和发射。
AI 中文摘要
等离子体纳米结构为增强原子级薄半导体中的光-物质相互作用提供了有效途径，其光学响应受限于亚纳米级的有源厚度。本文通过数值研究了单层二硫化钼（MoS2）与由薄氧化铝（Al2O3）和六方氮化硼（h-BN）间隔层分隔的尺寸可调金（Au）纳米立方体阵列耦合时的激子增强情况。通过改变纳米立方体边长，可在可见光谱范围内调节局域表面等离子体共振，以调制单层MoS2的A和B激子跃迁。结果表明，纳米立方体尺寸依赖的光谱红移可通过间隔层材料和厚度进一步控制，实现近场分布、载流子产生率、量子产率和辐射衰减增强的系统调谐。局域等离子体限制在B激子跃迁（605nm）处产生高达4.35的激发率增强，在A激子跃迁（650nm）处为3.66，辐射衰减率增强超过80，导致光致发光增强350倍。虽然A和B激子通道同时增强，但其相对贡献取决于纳米立方体尺寸、间隔层材料和厚度，表明是波长依赖的激子调制而非严格的激子选择性切换。这些发现确立了金纳米立方体阵列作为增强单层MoS2中激子载流子产生和发射的简单、可扩展且可调谐的等离子体平台。
英文摘要
Plasmonic nanostructures offer an effective route for enhancing light-matter interaction in atomically thin semiconductors, whose optical response is intrinsically limited by their sub-nanometer active thickness. Here, we numerically investigate excitonic enhancement in monolayer (ML) Molybdenum Disulfide (MoS2) coupled to size-tuned gold (Au) nanocube arrays separated by thin aluminum oxide (Al2O3) and hexagonal boron nitride (h-BN) spacer layers. By varying the nanocube side length, the localized surface plasmon resonance is tuned across the visible spectral range to modulate the A- and B-excitonic transitions of monolayer MoS2. We show that the nanocube-size-dependent spectral redshift can be further controlled through the spacer material and thickness, enabling systematic tuning of the near-field distribution, carrier generation rate, quantum yield, and radiative decay enhancement. Localized plasmonic confinement yields excitation-rate enhancements of up to 4.35 at B-excitonic transition (605 nm) and 3.66 at A-excitonic transition (650 nm), while the radiative decay-rate enhancement exceeds 80, leading to 350-fold photoluminescence enhancement. Although both A- and B-excitonic channels are enhanced simultaneously, their relative contributions depend on nanocube size, spacer material, and spacer thickness, indicating wavelength-dependent excitonic modulation rather than strict exciton-selective switching. These findings establish Au nanocube arrays as a simple, scalable, and tunable plasmonic platform for enhancing excitonic carrier generation and emission in ML MoS2.
Comments21 Pages, 5 Figures, 2 Tables
