Plasmonic hybridization properties in polyenes octatetraene molecules based on theoretical computation

Relationship of plasmonic properties of multiple clusters to molecular interactions and properties of a single cluster or molecule have become increasingly important due to the continuous emergence of molecular and cluster devices or systems.A hybrid phenomenon similar to plasmonic nanoparticle hybridization exists between two molecules with plasmon excitation modes.We use linear-response time-dependent density functional theory,real-time propagation time-dependent density functional theory,the plasmonicity index,and transition contribution maps(TCMs)to identify the plasmon excitation modes for the linear polyenes octatetraene with–OH and–NH_(2)groups and analyze the hybridization characteristics using charge transitions.The results show that molecular plasmon hybridization exists when the two molecules are coupled.The TCM analysis shows that the plasmon modes and hybridization result from collective and single-particle excitation.The plasmon mode is stronger,and the individual properties of the molecules are maintained after coupling when there is extra charge depose in the molecules because the electrons are moving in the molecules.This study provides new insights into the molecular plasmon hybridization of coupled molecules.

Light focusing in linear arranged symmetric nanoparticle trimer on metal film system

Benefiting from the induced image charge on film surface,the nanoparticle aggregating on metal exhibits interesting optical properties.In this work,a linear metal nanoparticle trimer on metal film system has been investigated to explore the novel optical phenomenon.Both the electric field and surface charge distributions demonstrate the light is focused on film greatly by the nanoparticles at two sides,which could be strongly modulated by the wavelength of incident light.And the influence of nanoparticle in middle on this light focusing ability has also been studied here,which is explained by the plasmon hybridization theory.Our finding about light focusing in nanoparticle aggregating on metal film not only enlarges the novel phenomenon of surface plasmon but also has great application prospect in the field of surface-enhanced spectra,surface catalysis,solar cells,water splitting,etc.

Realizing self-powered mechanical transmission control system via triboelectric nanogenerator and electrorheological fluid composed soft starter

Soft starters are effective devices used to provide overload protection for motors from large mechanical shocks during the start-up period.However,existing soft starters require additional power supplies,sensors,and complex control elements that pose serious challenges to the integration,versatility,and operability of mechanical transmission system.Herein,we propose a newly soft starter based on the triboelectric nanogenerator(TENG)and electrorheological fluid(ERF)to realize a self-powered mechanical transmission system.Both ERF’s rheological characteristic and the baffle structure play a role in the torque of device.Driven by TENG,the soft starter with optimized baffle achieves a 715%growth in transmission torque compared to that of the device without baffle.And a smooth start is obtained with transmission speeds ranging from 0%to 100%.In application demonstration,this triboelectric soft starter(TSS)has the capacity to gain a smooth operation of the high-speed motor.In contrast,the direct start generates an overshoot,leading to a break in the conveyor belt.The TSS designed in this work with the advantages of self-powered,highly integrated,easy to operate,and low cost,provides a prospective strategy for broadening the application of TENG in mechanical transmission systems.

Nanowire-supported plasmonic waveguide for remote excitation of surface-enhanced Raman scattering

Due to its amazing ability to manipulate light at the nanoscale,plasmonics has become one of the most interesting topics in the field of light–matter interaction.As a promising application of plasmonics,surface-enhanced Raman scattering(SERS)has been widely used in scientific investigations and material analysis.The large enhanced Raman signals are mainly caused by the extremely enhanced electromagnetic field that results from localized surface plasmon polaritons.Recently,a novel SERS technology called remote SERS has been reported,combining both localized surface plasmon polaritons and propagating surface plasmon polaritons(PSPPs,or called plasmonic waveguide),which may be found in prominent applications in special circumstances compared to traditional local SERS.In this article,we review the mechanism of remote SERS and its development since it was first reported in 2009.Various remote metal systems based on plasmonic waveguides,such as nanoparticle–nanowire systems,single nanowire systems,crossed nanowire systems and nanowire dimer systems,are introduced,and recent novel applications,such as sensors,plasmon-driven surface-catalyzed reactions and Raman optical activity,are also presented.Furthermore,studies of remote SERS in dielectric and organic systems based on dielectric waveguides remind us that this useful technology has additional,tremendous application prospects that have not been realized in metal systems.