Plasmonic metal‐organic frameworks

Plasmonic metal‐organic frameworks are composite nanoparticles comprising plasmonic metal nanoparticles(NPs)embedded within a metalorganic framework(MOF)matrix.As a result,not only the functionalities of the individual components are retained,but synergistic effects additionally provide improved chemical and physical properties.Recent progress in plasmonic MOFs has demonstrated the potential for nanofabrication and various nanotechnology applications.Synthetic challenges toward plasmonic MOFs have been recently addressed,resulting in new opportunities toward practical applications,such as surface‐enhanced Raman scattering,therapy,and catalysis.The impact of key parameters(thermodynamic vs.kinetic)on the synthetic pathways of plasmonic MOFs is reviewed,while providing insight into related progress toward structure‐derived applications.

Low cross-talk, deep subwavelength plasmonic metal/insulator/metal waveguide intersections with broadband tunability

We suggest a low cross-talk plasmonic cross-connector based on a metal/insulator/metal cavity and waveguides.We separately investigate the isolated cavity mode, the waveguide mode, and the combination of cavity and waveguide modes using a finite-different time-domain method. Due to resonant tunneling and the cutoff frequency of the odd waveguide mode, our proposed structure achieves a high throughput transmission ratio and eliminates cross-talk. Furthermore, the proposed structure has a broadband tunability of 587 nm, which can be achieved by modulating the cavity air gap thickness. This structure enables the miniaturization of photonic integrated circuits and sensing applications.

Fano resonance and magneto-optical Kerr rotaion in periodic Co/Ni complex plasmonic nanostructure

we report a pure rerromagneuc metallic magnetopiasmonic structure consisting or two-dimensional oraerea Ni nanodisks array on Co film.With a sufficient height of the nanodisks,a steep and asymmetric Fano resonance can be excited in this structure.We attribute the fascinating spectral lineshape to the strong coupling between the excitation of surface plasmon polaritons at the interface and the localized surface plasmon resonance of nanodisks.The conclusion is fully confirmed by spectrum measurements in nanostructures with different heights.Furthermore,the enhancement and sign of the magneto-optical Kerr rotation in this structure are significantly modified by the Fano resonance.

Surface Plasmon Interference Lithography Assisted by a Fabry-Perot Cavity Composed of Subwavelength Metal Grating and Thin Metal Film

A surface plasmon interference lithography assisted by a Fabry-Perot （F-P） cavity composed of subwavelength metal gratings and a thin metal fihn is proposed to fabricate high-quality nanopatterns. The calculated results indicate that uniform straight interference fringes with high contrast and high electric-field intensity are formed in the resist under the F-P cavity. The analyses of spatial frequency spectra illuminate the physical mechanism of the formation for the interference fringes. The influence of the F-P cavity spacing is discussed in detail. Moreover, the error analyses reveal that all parameters except the metal grating period in this scheme can bear large tolerances for the device fabrication.

A review on plasmonic enhancement of activity and selectivity in electrocatalytic CO_(2)reduction

Utilizing plasmonic effects to assist electrochemical reactions exhibits a huge potential in tuning the reaction activities and product selectivity,which is most appealing especially in chemical reactions with multiple products,such as CO_(2)reduction reaction(CO_(2)RR).However,a comprehensive review of the development and the underlying mechanisms in plasmon-assisted electrocatalytic CO_(2)RR remains few and far between.Herein,the fundamentals of localized surface plasmonic resonance(LSPR)excitation and the properties of typical plasmonic metals(including Au,Ag,and Cu)are retrospected.Subsequently,the potential mechanisms of plasmonic effects(such as hot carrier effects and photothermal effects)on the reaction performance in the field of plasmon-assisted electrocatalytic CO_(2)RR are summarized,which provides directions for the future development of this field.It is concluded that plasmonic catalysts exhibit potential capabilities in enhancing CO_(2)RR while more in situ techniques are essential to further clarify the inner mechanisms.

New design of triplexer based on metal–insulator–metal plasmonic ring resonators

In this work, we propose a new design of all-optical triplexer based on of metal–insulator–metal（MIM） plasmonic waveguide structures and ring resonators. By adjusting the radii of ring resonators and the gap distance, certain wavelengths can be filtered out and the crosstalk of each channel can also be reduced. The numerical results show that the proposed MIM plasmonic waveguide structure can really function as an optical triplexer with respect to the three wavelengths, that is, 1310, 1490, and 1550 nm, respectively. It can be widely used as the fiber access network element for multiplexer–demultiplexer wavelength selective in fiber-to-the-home communication systems with transmission efficiency higher than 90%. It can also be a potential key component in the applications of the biosensing systems.

Graphene-supported manipulation of surface plasmon polaritons in metallic nanowaveguides

We investigate the electrically controlled light propagation in the metal–dielectric–metal plasmonic waveguide with a sandwiched graphene monolayer. The theoretical and simulation results show that the propagation loss exhibits an obvious peak when the permittivity of graphene approaches an epsilon-near-zero point when adjusting the gate voltage on graphene. The analog of electromagnetically induced transparency(EIT) can be generated by introducing side-coupled stubs into the waveguide. Based on the EIT-like effect, the hybrid plasmonic waveguide with a length of only 1.5 μm can work as a modulator with an extinction ratio of ～15.8 d B, which is 2.3times larger than the case without the stubs. The active modulation of surface plasmon polariton propagation can be further improved by tuning the carrier mobility of graphene. The graphene-supported plasmonic waveguide system could find applications for the nanoscale manipulation of light and chip-integrated modulation.

Integrated hetero-nanoelectrodes for plasmon-enhanced electrocatalysis of hydrogen evolution

Hetero-nanostructures of plasmonic metals and semiconductors have attracted increasing attention in the field of photocatalysis.However,most of the hetero-nanostructured catalysts are randomly arranged and therefore require comprehensive structural design for optimizing their properties.Herein,we report the robust construction of hierarchical hetero-nanostructures where gold(Au)nanorods and molybdenum disulfide(Mo S_(2))quantum sheets(QSs)are integrated in highly ordered arrays.Such construction is achieved through porous anodic alumina(PAA)template-assisted electrodeposition.The as-fabricated hetero-nanostructures demonstrate exciting electrocatalysis towards hydrogen evolution reaction(HER).Both plasmon-induced hot-electron injection and plasmonic scattering/reabsorption mechanisms are determinative to the enhanced electrocatalytic performances.Notably,broadband photoresponses of HER activity in the visible range are observed,indicating their superiority compared with random systems.Such integrated hetero-nanoelectrodes could provide a powerful platform for conversion and utilization of solar energy,meanwhile would greatly prompt the production and exploration of ordered nanoelectrodes.

Highly sensitive and selective two-photon sensing of cartap using Au@Ag core-shell nanoparticles

A highly sensitive and selective two-photon sensing scheme for detection of cartap was developed by using Au@Ag bimetallic core-shell nanoparticles.Cartap was found to induce the aggregation of Au@Ag nanoparticles and up to 700-fold enhancement in two-photon photoluminescence.Huge enhancement in two-photon photoluminescence allows achieving a detection limit of as low as 0.0062 mg/kg,which is better than the conventional colorimetric methods.This two-photon sensing scheme has a broad dynamic range and displays excellent selectivity in detection of cartap against over other ten kinds of commonly used insecticides.