Ultra-narrowband circular dichroism in all-dielectric chiral nanohole arrays based on griddings and monolayer MoS2
Ultra-narrowband circular dichroism in all-dielectric chiral nanohole arrays based on griddings and monolayer MoS2
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DOI：
10.1016/j.optcom.2023.129962
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发表时间：
2023-10-01
影响因子：
2.4
通讯作者：
Wang，Yongkai
中科院分区：
文献类型：
--
作者：
Liang，Lei;Sun，Jialin;Wang，Yongkai
金属手性纳米结构具有很强的圆二色性，在偏振转换、负折射材料和手性分子检测等方面具有重要的应用前景。然而，具有损耗的金属手性纳米结构难以产生动态可调谐的超窄带圆二色性信号，这极大地限制了其在传感领域的应用。本文将具有相变特性的MoS2和Sb2S3引入到基于网格的全介质手性纳米孔阵列（ACNAs）中，以产生动态可调谐的超窄带圆二色性信号。模拟结果表明，ACNAs/MoS2在可见光范围内产生两个较强的窄带CD信号。最大CD强度可达0.75，最大半宽度可达0.8 nm。电场分布表明，两个CD信号主要由导模共振引起。超窄带CD信号既取决于其几何参数，又可以通过改变光的入射角和Sb2S3的结晶状态来实现动态调节。通过分析不同浓度SARS-CoV-2溶液对CD光谱的影响，评价了该传感器的传感特性。这些发现将有助于设计具有动态可调超窄带CD的全介电手性纳米结构，并促进其在生物传感中的应用。
The strong circular dichroism (CD) of metallic chiral nanostructures can be applied to polarization conversion, negative refraction materials, and chiral molecule detection. However, metallic chiral nanostructures with losses struggle to produce dynamically tunable ultra-narrow band circular dichroism signals, which greatly limits their applications in sensing. In this paper, the MoS2and Sb2S3with phase change characteristics are introduced into all-dielectric chiral nanopore arrays (ACNAs) based on gridding to generate dynamically tunable ultra-narrow band circular dichroism signals. Simulation results show that ACNAs/MoS2produce two strong narrow-band CD signals in the visible range. The maximum CD intensity can reach 0.75, and the maximum half-width can reach 0.8 nm. The electric field distribution indicates that two CD signals are mainly caused by the guided mode resonance. The ultra-narrow band CD signals both lie on their geometric parameters and can realize the dynamic regulation by changing the incidence angle of lights and the crystalline state of Sb2S3. Furthermore, the sensing characteristics of this device were evaluated by analyzing the effects of different concentrations of SARS-CoV-2 solutions on the CD spectra. These findings will facilitate the design of all-dielectric chiral nanostructures with dynamically tunable ultra-narrow band CDs and facilitate their applications in biosensing.