Ag Nanorods Research Articles

Polarization‐Controlled Chromo‐Encryption

AbstractThe response of simple plasmonic nanorods to polarized illumination is studied in detail. Depending on the orientation of that polarization with respect to the symmetry axes of the nanostructure, a chiral response can occur, which can be analyzed through a second polarizer, in order to control the spectral response of the system. Specifically, for the Ag nanorods fabricated here, a broad variety of colors can be produced that cover half of the chromaticity diagram. Depending on the illumination and detection polarizations, these colors range from white to vivid colors or even black, in spite of the fact that the material at hand does not absorb much light. By exploiting two additional degrees of freedom, namely the nanorod length and its orientation within the unit cell, it is possible to produce a very rich palette of optical effects that are controlled by the polarization of light. Their utilization to reproduce artworks is demonstrated, together with their operation as encrypting system, where the polarizations are used as keys and the message is encrypted in a quaternary color subset.

Highly Reliable Threshold Switching Characteristics of Surface-Modulated Diffusive Memristors Immune to Atmospheric Changes.

Active cation-based diffusive memristors featuring essentially volatile threshold switching have been proposed for novel applications, such as a selector in a one-selector-and-one-resistor structure and signal generators in neuromorphic computing. However, the high variability of the switching behavior, which results from the high electroforming voltage, external environmental conditions, and transition to the non-volatile switching mode in a high-current range, is considered a major impediment to such applications. Herein, for the first time, we developed a highly reliable threshold switching device immune to atmospheric changes based on an ultraviolet-ozone (UVO)-treated diffusive memristor consisting of Ag and SiO2 nanorods (NRs). UVO treatment forms a stable water reservoir on the surface of SiO2 NRs, facilitating the redox reaction and ion migration of Ag. Consequently, diffusive memristors possess reliable switching characteristics, including electroforming-free, repeatable, and consistent switching with resistance to changes in ambient conditions and compliance levels during operation. We demonstrated that our approach is suitable for various metal oxides and can be used in numerous applications.

Effect of various metallic nanoparticles on plasmon-enhanced solar absorption efficiency.

Solar thermal conversion technology has attracted significant attention because it ensures sustainable and modern clean energy generation. The usage of plasmonic nanofluids as the working media is a useful strategy to collect solar energy. In this study, the optical properties of various individual nanospheres (NPs) and nanorods (NRs)--Au, Ag, Cu, Fe, Mg, Mn, Mo, Pb, Ti, Li, and Al--and their effect on the solar absorption efficiency factor (SAEF) with a solar wavelength between 300nm and 1100nm are determined using COMSOL Multiphysics software. For NPs, the SAEF is divided into three parts. In the first part with a radius lower than 35nm, an Li NP has the highest SAEF of 1.3992. In the second part, with a radius between 35nm and 50nm, the Au and Cu NPs have the highest SAEFs of 1.1963 and 1.2469, respectively. In the third part, with a radius between 50nm and 90nm, the maximum SAEFs of Fe (1.5682 at radius of 75nm), Pt (1.4914 at radius of 90nm), Ti (1.4348 at radius of 75nm), and Mn (1.4614 at radius of 75nm) can be obtained. Compared to NPs, the SAEF of an NR greatly depends on the aspect ratio (AR) and the effective radius (r e f f ). We observe that the SAEFs of Ag, Al, Au, Cu, Fe Mg, Mn, Mo, and Ti NRs are much stronger than that of corresponding NPs with the same r e f f . The results obtained from the present study provide fundamental information and guidelines to choose optimal NPs for enhancements in solar energy harvesting.

Template-directed growth of Ag nanostructures: soft templates versus hard templates.

Hard template-directed growth methods present a compelling route for the synthesis of Ag nanostructures with precise size control. Meanwhile, soft template methods are effective and flexible for the synthesis of Ag nanostructures with various morphologies. However, the role of the soft template is ambiguous and obviously neglected in hard template-directed growth processes due to the strong confinement effect of the hard template, limiting the diversity of Ag nanostructures that can be obtained. Herein, we design Au nanoframes with deformable head structures as a hard template while using cetyltrimethylammonium chloride as a soft template, to direct the growth of Ag atoms on Au nanobipyramid seeds. When using the Au nanoframes with a closed head, the longitudinal growth of the Ag atoms is clearly limited by the hard template, leading to the formation of thick Ag nanorods with a five-fold twinned structure. The soft template starts to influence the growth process when the head structure of the Au nanoframes becomes hollow. In particular, the confinement effect of the hard template can be completely broken by selectively strengthening the role of the soft template, promoting the production of slender Ag nanorods similar to the results obtained in the absence of the hard template. Our results indicate that the morphology of the Ag nanostructures depends on the competition between the qualitatively confined energies of the hard and soft templates during the template-directed growth process. Moreover, this confined growth mechanism is also verified by the successful construction of various Ag nanostructures. The understanding of the collaborative competition mechanism between the soft and hard templates presents a great opportunity to construct novel Ag nanostructures through a template-directed method.

A facile route to Janus nanorods via redox-assisted ripening

In the synthesis of Janus Ag nanorods, Ag promotes the reaction between HQ and oxygen and at the same time, and the redox reaction provides an additional driving force for oxidative dissolution and reductive deposition.

Synthesis of bone-shaped Au–Ag2S metal-semiconductor nanorods and their photocatalytic application

In this work, we describe an aqueous synthetic strategy for producing bone-shaped Au − Ag2S metal-semiconductor hybrid nanorods. Specifically, Au nanorods were first synthesized and used as seeds to synthesize bone-shaped Au − Ag nanorods by selectively overgrowing Ag shells at both ends of Au nanorods. Through the site-selective sulfidation strategy using Na2S aqueous solution, the Au − Ag bimetallic nanorods were transformed into Au–Ag2S metal–semiconductor hybrid nanorods. When used as photocatalysts for the photooxidative degradation of methylene blue (MB) under sunlight irradiation, the Au–Ag2S hybrid nanorods showed excellent photocatalytic performance due to the synergistic action of metal and semiconductor components.

Surface-enhanced Raman Scattering and Localized Surface Plasmon Resonance Detection of Aldehydes Using 4-ATP Functionalized Ag Nanorods

Formaldehyde, acetaldehyde, and benzaldehyde are well-known carcinogens affecting human health adversely. Thus, there is a need for efficient detection of these aldehydes. This work uses 4-aminothiophenol (4-ATP) functionalized silver nanorods (Ag NRs) to detect these three aldehydes. The detection mode includes localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS). The LSPR band of 4-ATP functionalized Ag NRs shows a linear decrease in absorbance with the increase in formaldehyde and acetaldehyde concentrations. A sensitivity of 0.96 and 0.79 ΔA/mM for formaldehyde and acetaldehyde were obtained. In the case of benzaldehyde, a nearly exponential decrease in absorbance with the increase in concentrations was observed. Above 98.4 μM concentration, the absorbance diminishes completely. The LoD for formaldehyde and acetaldehyde detection using LSPR is 33.8 and 24.6 μM, respectively. The SERS studies reveal that the 4-ATP binds to Ag NRs through both –SH and –NH2 groups and facilitates the inter-particle charge transfer process. The appearance of b2 modes of vibration for 4-ATP evidences this charge transfer process. In the presence of aldehydes, the change in the band shape, relative intensities, and band position were observed primarily in b2 modes of vibration, evidencing the modulation in the charge transfer process. These remarkable changes were seen in μM concentration of aldehydes. Therefore, detection of these aldehydes with 4-ATP functionalized Ag NRs using SERS is possible in concentrations as low as ~ 1 μM.

Effects of Thermal Annealing on Optical and Microscopic Ferromagnetic Properties in InZnP:Ag Nano-Rods.

InZnP:Ag nano-rods fabricated by the ion milling method were thermally annealed in the 250~350 °C temperature range and investigated the optimum thermal annealing conditions to further understand the mutual correlation between the optical properties and the microscopic magnetic properties. The formation of InZnP:Ag nano-rods was determined from transmission electron microscopy (TEM), total reflectivity and Raman scattering analyses. The downward shifts of peak position for LO and TO modes in the Raman spectrum are indicative of the production of Ag ion-induced strain during the annealing process of the InZnP:Ag nano-rod samples. The appearance of two emission peaks of both (A0 X) and (e, Ag) in the PL spectrum indicated that acceptor states by Ag diffusion are visible due to the effective incorporation of Ag-creating acceptor states. The binding energy between the acceptor and the exciton measured as a function of temperature was found to be 21.2 meV for the sample annealed at 300 °C. The noticeable MFM image contrast and the clear change in the MFM phase with the scanning distance indicate the formation of the ferromagnetic spin coupling interaction on the surface of InZnP:Ag nano-rods by Ag diffusion. This study suggests that the InZnP:Ag nano-rods should be a potential candidate for the application of spintronic devices.

Toward High-Power Output of Generators: High-Power-Factor Ag2Te-Ag Thermoelectric Thin Films Using a Layer-by-Layer Method.

The power factor is key to improving the performance of thin-film thermoelectric generators as power sources. The expected large power factor of Ag2Te testifies to its application potential. In this study, Ag2Te-Ag thin films were fabricated using a layer-by-layer method for controlling their composition and improving their thermoelectric properties. In contrast to the traditional low-temperature monoclinic structure, orthorhombic Ag2Te thin films with Ag nanoparticles on top were obtained by the reaction between Ag and Te nanorod thin films. Analysis of the structural and thermoelectric properties showed increased carrier concentration and enhanced electrical properties of the films, while the structural transition between the orthorhombic structure and the face-centered cubic structure improved the films' electrical stability over a wide range of temperatures. Owing to the special structure, a competitive high power factor of 4.66 mW m-1 K-2 at 668 K was achieved. The proposed approach improves the electrical properties of n-type Ag2Te thin films, owing to the special Ag2Te-Ag structure, and provides guidance for designing high-output-power thin-film thermoelectric generators.

An effective one-step aqueous-phase synthesis of finely controllable Ag nanorods with tunable short aspect ratios and electronic dynamics properties

Ag nanorods with finely controllable aspect ratios (especially 1–5) were synthesized in high yield via an effective one-step aqueous-phase method, in which the longitudinal plasmon modes in visible and infrared regions of short Ag nanorods were well adjustable. Meanwhile, excitation wavelength- and excitation fluence-dependent electronic dynamics of short Ag nanorods were acquired and were found to be regular. This suggested that short Ag nanorods would have great potential in plasmonic and photoelectronic fields.

Double-Tetrahedral DNA Probe Functionalized Ag Nanorod Biointerface for Effective Capture, Highly Sensitive Detection, and Nondestructive Release of Circulating Tumor Cells.

Circulating tumor cells (CTCs) are indicative of tumorigenesis, metastasis, and recurrence; however, it is still a great challenge to efficiently analyze the extremely rare CTCs in peripheral blood. Herein, a novel nanobiointerface integrating high affinities of arrayed silver nanorods (Ag NRs) and double-tetrahedral DNA (DTDN) probes by a clever strategy is proposed for the efficient capture, highly sensitive detection, and nondestructive release of CTCs. Under the optimal conditions, the DTDN-probe-functionalized Ag NRs nanobiointerface can capture 90.2% of SGC-7901 cells in PBS, and the capture efficiency is 2.8 times and 50 times those of a DTDN-probe-functionalized Ag film and unfunctionalized Ag NRs, respectively, benefiting from the nanorough interface of the Ag NRs array and multivalent recognition of the DTDN probe. In addition, 93.4% of cells was released via Zn2+-assisted DNAzyme cleavage, and the viability of the postreleased CTCs is about 98.0%. The potential practicality of the nanobiointerface for testing CTCs in blood was further characterized by spiking SGC-7901 cells in leukocytes collected from human blood, and the results show that 83.8% capture efficiency, 91.2% release efficiency, and single-cell detection limit were achieved, which indicates that the nanobiointerface has great potential in clinical applications for reliable CTC analyses.

P-056 The reproductive toxicity of alginate coated silver nano-rod on sperm

Abstract Study question What is the toxic effects of Au@Ag core-shell NR on sperm function? Summary answer Although sperm count and morphology did not differ significantly, changing the shape and envelope of the silver nanostructure did not reduce its toxicity. What is known already Spermatogenesis is a developmental process of germ cell reproduction that depends on hormonal or dynamic interplays between sertoli cells and germ cells. Silver is the most common noble metal used in the synthesis of nanoscale materials, particularly in room sprays, cosmetics, toys, clinical catheters, and wound dressings. The increasing usability of silver nanoparticles (Ag NP) has increased human exposure. Many studies have demonstrated that Ag nanoparticles, depending on their shape, size, and concentration, have cytotoxic effects that reduce cell viability. The toxicity of silver Nano-Rod by deformation and coating with alginate has been studied. Study design, size, duration Forty-eight male mice were divided into five groups (two treatments, two shams, and one control). The treated groups received the Ag Nano-Rod at a dose of 1.5 mg/kg/day intraperitoneally for fourteen and thirty-five days. The sham groups were treated with identical amounts and days, and the control group received no material. Finally, the cauda epididymis of the animals was removed. Participants/materials, setting, methods In the present study, Ag Nano-Rod were characterized by HR-TEM, FT-IR, UV-visible, XRD and ICP-MS. Sperm analysis, including count, motility, viability, and morphology, was studied according to the criteria of WHO. A phase-contrast microscope was used to count the spermatozoa and assess their motility. Viability and morphology were examined by eosin-nigrosin and papanicolaou staining, respectively. TUNEL assay and gene expression for apoptotic and autophagic markers were also performed. Main results and the role of chance High magnification images TEM were obtained. According to this, the Ag nanostructure was rod-shaped and the average size of the particles was 50nm. The UV-visible confirms the formation of the synthesized nanosilver (rod shape). The change in nanostructure coating from CTAB to alginate was studied by FTIR analysis, and XRD proved the presence of silver in the composition. The results of sperm analysis showed that there was no significant decrease in sperm count and morphology but the parameters of motility and viability of the nanosilver groups showed a significant decline compared to the control group (P < 0.05). Assessment of sperm DNA fragmentation by the TUNEL assay showed that the nanosilver groups had significantly higher DNA fragmentation and the real-time PCR results also confirmed this. Expression of autophagic and apoptotic markers indicates activation of the apoptosis pathway compared to the autophagy pathway. The expression of LC3 and Beclin-1 (markers that initiate and continue the autophagy) was reduced compared to the sham and control groups. Also, examination of apoptotic pathway genes showed a decrease in Bcl-2 expression and an increase in Bax and caspase-3 expression. Limitations, reasons for caution This study requires further research, including protein expression in these two pathways. Wider implications of the findings This study investigated the acute (14 days) and chronic (35 days) effects of silver nanorod on reproductive toxicity, which can lead to significant changes in sperm quality. This reduction in quality was observed mainly in the chronic phase and severely affected sperm motility. Trial registration number Not Applicable

SERS/electrochemical dual-mode biosensor based on multi-functionalized molybdenum disulfide nanosheet probes and SERS-active Ag nanorods array electrodes for reliable detection of cancer-related miRNA

The reliable detection of cancer-related biomarkers is essential for accurate diagnosis of cancers. SERS/electrochemical dual-mode sensing can provide a powerful tool to achieve more accurate detection, however, the in situ facile dual-mode detections have rarely been reported. Herein, a novel SERS/electrochemical dual-mode biosensor based on multi-functionalized molybdenum disulfide nanosheet (mF-MoS2 NS) probes and SERS-active Ag nanorods (AgNRs) array electrode was proposed for in situ dual-mode detection of gastric cancer-related miR-106a. The AgNRs array coated by the mF-MoS2 NSs shows significantly improved electrochemical and SERS stability in electrolyte solutions, and the “mF-MoS2 NSs probes-miRNA-AgNRs array electrodes” sandwich structured SERS/electrochemical sensor was built for stable, in-situ dual-mode detection of miR-106a. The sensor shows good selectivity for differentiating miR-106a from the single-base mismatched nucleic acid, and possesses linear calibration curves of both SERS and electrochemical sensing modes with the limit of detections of 67.44 fM and 248.01 fM, respectively. The reliable assay of miR-106a in human serum indicates that the proposed SERS/electrochemical dual-mode sensor is suitable for detecting complex samples and can be a potential high-sensitive and reliable tool for clinical diagnosis of early cancers.

Hierarchical mesoporous SnO2/BiVO4 photoanode decorated with Ag nanorods for efficient photoelectrochemical water splitting

Bismuth vanadate has been extensively investigated as a potential visible light photoanode for PEC water splitting. The performance of BiVO4 is restricted by fast charge recombination and slow oxygen evolution reaction kinetic. To address these issues, hierarchical SnO2 (HSN) mesoporous support is developed via a novel sol-electrophoretic approach, and BiVO4 film is decorated with silver nanorods (Ag NRs). The photocurrent density of HSN/BiVO4 photoanode is 3.98 mA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE) and onset potential (Vonset) of 0.5 V vs. RHE. The PEC performance is attributed to the appropriate band alignment between SnO2 and BiVO4, as well as the hierarchical structure of SnO2. Ag-HSN/BiVO4 photoanode shows photocurrent density of 4.30 mA/cm2 at 1.23 V vs. RHE and Vonset of 0.28 V vs. RHE. The enhanced photocurrent and negatively shifted Vonset can be attributed to radiative localized surface plasmon resonance decay and catalytic effect of Ag NRs, respectively.

Ultrafast changes in effective permittivity of hyperbolic metamaterials and related multi-resonance-induced ultrafast process excited by femtosecond pulses.

Hyperbolic metamaterials (HMMs) exhibit rich optical nonlinear responses for the epsilon-near-zero (ENZ) and anisotropy. In this study, we extract the time-dependent change in the effective permittivity of an Ag nanorod array under femtosecond pulses pumping around its ENZ wavelength. The transmittance and transient absorption spectra measured by s- and p-polarizations are used in the extraction process. We experimentally confirm the existence of an ultrafast recovery process with a relaxation time of 0.24 ps in the transient absorption spectra. The calculation based on the extracted nonlinear effective permittivity indicates that the ultrafast signal originates from the superposition of two slower recovery processes, with relaxation times of 0.74 ps and 1.19 ps, respectively. The results indicate that when the responses of two nonlinear processes have different signs and recovery speeds, their superposition may cause faster signal recovery in the combined process than in the two individual processes.

Intelligent peptide-nanorods against drug-resistant bacterial infection and promote wound healing by mild-temperature photothermal therapy

• Dap@Au/Ag NRs can release Ag + and Dap with H 2 O 2 etching to kill bacterial. • Dap@Au/Ag NRs have good biocompatibility before and after etching. • The antibacterial property was significantly improved with PTT and H 2 O 2 etching. • Mild temperature PTT can effectively reduce the incidence of skin burns. Due to the abuse of antibiotics, bacteria produce serious drug resistance, which makes the existing clinical antibiotic treatment scheme fail and seriously endangers human health. The construction of antimicrobial nanometer systems including antimicrobial peptides and antimicrobial nanomaterials has become the focus of research on new antimicrobial agents, and may significantly improve the antimicrobial efficiency. In this study, we successfully explored a novel antimicrobial nano-system Dap@Au/Ag nanorods (Dap@Au/Ag NRs) based on gold nanorods, and investigated the antimicrobial properties of this novel antimicrobial agent with methicillin-resistant Staphylococcus aureus (MRSA) as the experimental strain. Under the action of H 2 O 2 , Dap@Au/Ag NRs can considerably release silver ions and antimicrobial peptides (Dap), destroying the integrity of the MRSA membrane and resulting in content leakage and bacterial death. Furthermore, in vivo and in vitro experiments showed that after a certain intensity of laser irradiation (808 nm, 0.8 W/cm 2 , 40–60 s), the antibacterial properties of Dap@Au/Ag NRs were significantly improved by using gold nanorods with good photothermal effect. At the same time, compared with traditional photothermal therapy (PTT), we found that laser irradiation with the appropriate intensity was given at the initial stage of infection and controlled at a mild temperature (below 47 °C), it not only significantly inhibited the growth of MRSA, prevented large area of wound ulceration and promoted wound healing, but also had no obvious thermal damage to the wound surface and surrounding skin. The results showed that novel antibacterial nano-system Dap@Au/Ag NRs have significant bactericidal properties, and can be used as a potential promising antimicrobial agent, which provides a new strategy for facilitating and enhancing the effective antimicrobial efficiency to inhibit drug-resistant bacterial infection.

Nanoporous silver nanorods as surface-enhanced Raman scattering substrates

Structures with dense nanopores are desirable as surface-enhanced Raman scattering (SERS) sensing substrates because the nanopores can behave as both analyte containers and SERS-active sites (known as hot spots). Inspired by the dealloying process to prepare nanoporous structures through selectively removing active metals from their alloy, we developed a method to prepare nanoporous Ag nanorods through chemical reduction of the electrodeposited Ag7O8NO3 nanorods using a strong reducing agent (e.g., NaBH4). The length and the thickness of the Ag7O8NO3 nanorods could be controlled by the electrodeposition voltage and time. Nitrogen and oxygen elements were immediately removed from Ag7O8NO3 nanorods by the reducing agent, leaving behind a tremendous number of nanopores with a mean size of 20 nm, which can efficiently trap and enrich analytes. Meanwhile, the densely packed nanopores can behave as SERS hot spots to provide strong SERS enhancement. The nanoporous Ag nanorods as SERS substrates were used to sensitively detect adenine, spike glycoprotein, and polychlorinated biphenyls pollutants, as well as identify different types of bacteria. The simple fabrication process and the outstanding SERS performance of the nanoporous Ag nanorods make them promising candidates for SERS applications towards trace detection of pollutants, narcotics, food additives, and biomolecules.

Extinction and scattering of light by nonspherical plasmonic particles in absorbing media

Electromagnetic scattering by spheres embedded in an absorbing medium has attracted much attention and has been solved recently by an extension of conventional Lorenz-Mie (LM) theory. By contrast, no relevant studies have been published for nonspherical absorbing particles. To the best of our knowledge, we present the first T-matrix method (TMM) formalism and relevant computer simulations for nonspherical particles embedded in an absorbing host. We also derive analytical electrostatic and improved electrostatic approximations (EA and IEA) for small spheroids in an absorbing host. To exemplify the developed theory and computer codes, we consider randomly oriented prolate and oblate Au and Ag nanospheroids, cigar-like nanorods, and nanodisks embedded in a water-like absorbing medium with the complex refractive index 1.33+i(0-0.3), in a lossy poly(3-hexylthiophene) (P3HT) matrix, and the lossless poly(methyl methacrylate) (PMMA). We analyze two far-field optical observables inherent to the particles: the extinction cross section and the normalized 4 × 4 scattering matrix. Specifically, we discuss the spectral extinction, the phase function, and the depolarization ratio, which characterizes the cross-polarized intensity of scattered light. To normalize the phase function, we also calculated the effective far-field scattering cross section. For maximal size parameters less than 1, IEA and TMM cross section spectra agree perfectly, independently on the aspect ratio (1–10) and imaginary part of host absorption (0–0.3). Thus, IEA provides a simple, accurate, and user-friendly alternative to TMM codes when the maximal particle size is less than 200 nm, irrespective of the host absorption. The general effect of increasing host absorption is to decrease and broaden the plasmonic extinction and scattering peaks, independently of the particle shape, material (Au or Ag), and the size correction of optical constants. However, in the lossy P3HT matrix, the dominant plasmonic resonances (PRs) are red-shifted and narrowed compared to the corresponding peaks in PMMA. In particular, the absolute FWHM of 12–20 nm and the relative FWHM/PR values of 1.9–2.5% were found for prolate Au and oblate Ag particles embedded in P3HT. This unusual narrowing is explained by the extreme spectral dependence of P3HT absorption. The phase function of Au and Ag nanorods is symmetrical irrespective of the aspect ratio and the host absorption, but it does not follow the Rayleigh law. The host absorption decreases the spectral maxima of the depolarization ratio and shifts them slightly to the red.

Numerical simulation of strong coupling between silver nanorod and dielectric layer detected by electron energy loss spectrum

The strong coupling phenomenon between surface plasmons and quantum emitters has received extensive attention in recent years. It is usually studied by the far-field spectral detection method such as scattering, absorption, and fluorescence. In the electron energy loss spectroscopy (EELS), highly focused electron beams are used for implementing the local detection on a sub-nanometer scale, which can be more effective to study strong coupling. In this work, the electron energy loss spectrum of silver nanorods, dielectric materials and their composite core-shell nanostructures are theoretically simulated respectively, and the energy and mode characteristics of surface plasmons on the silver nanorods and the excitation characteristics of dielectric materials are obtained. The electron energy loss spectrum of surface plasmon is basically consistent with the related experimental result. Rabi splitting of spectral peaks is observed in the electron energy loss spectra of the above composite structures, and the effect of Ag nanorod size on Rabi splitting is explored. The strong coupling between the radiative dipolar and non-radiative higher-order plasmon with the excitation of the dielectric materials in the infrared and visible band is discussed, and the corresponding dispersion relation is analyzed with the coupled oscillator mode. Furthermore, the plexciton caused by strong coupling are discussed from the perspective of spatial distribution of loss spectrum imaging. Our study builds the basis for further theoretical study, and can guide the further experimental research.

Broadband absorption of monolayer MoS2 in visible region using a tetramerized nanorod metasurface

High-efficient broadband absorption of the monolayer MoS2 is achieved by using a tetramerized nanorod metasurface (TNM), and the average absorption of 64.5% for the monolayer MoS2 can be obtained in the visible range of 400–750 nm. The unit cell of the TNM consists four Ag nanorods with different diameters, the incident light can be selectively absorbed by the monolayer MoS2 due to the magnetic resonance associated with the individual Ag nanorod, and broadband absorption of the monolayer MoS2 is realizable due to the cooperative magnetic resonances related to the tetramerized Ag nanorods. In addition, the absorption of the monolayer MoS2 is robust to the variation of the structural parameters, and it exhibits wide-angle and polarization-independent features.