Research On Surface Plasmon Polaritons Field Enhancement And Its Optical Application On Metal/MXene

Noble metal nanoparticles and two-dimensional（2D）nanomaterials have been widely concerned due to their unique optical properties,and they have wide application prospects in optical field.Silver nanoparticles（Ag NPs）are widely used in surface plasmon resonance sensing and surface-enhanced Raman scattering because of their unique plasmonics properties.Ti₃C₂T_x（MXene）and black phosphorus（BP）,as popular 2D materials,have their unique optical properties.MXene has been widely studied due to its advantages of wide absorption band and high electron mobility.BP has attracted extensive attention due to its advantages of in-plane anisotropy and strong confinement electric field.And they have important application value in the designing of micro-nano optical devices.Surface plasmons polaritons（SPPs）is a kind of electromagnetic oscillation generated by the interaction of free electrons and electromagnetic waves on the metal surfaces,when external electromagnetic waves are irradiated to the surface of metal and medium.Surface plasmon polaritons have typical strong local electric field enhancement effect.In this paper,the local near-field enhancement phenomenon of Ag NPs,MXene and BP materials and their application in the optical field are investigated by using the finite difference time domain（FDTD）method and experimental method.The main contents of this paper are as follows:（1）A composite MXene/BP-based metasurface,consisting of Ti₃C₂T_x and BP layers,is proposed for investigating the transmission optical responses and electric field by using the FDTD method in the microwave band.The research results show that the Fano resonance-like spectra can be observed when the coupling of surface plasmons（SPs）on the BP and MXene layers appears.The Fano resonance-like spectra disappears,when the width of BP layer is equal to the width of MXene layer.And at the moment,only the SPs of MXene layer is excited.Furthermore,the field enhancement,using the Fano resonance-like optical responses,can be improved by an order of magnitude through adjusting the structural parameters and the polarization of incident light for the structure.（2）The high sensitivity detection of glucose detection based on silver nanoparticles is studied through FDTD and experimental methods.The results show that the transmission of the solution gradually decreases as the number of Ag NPs increases,when the concentration of glucose is constant.And the transmission spectra show slight red shift with the increasing of the glucose concentration.Moreover,the simulation results are in agreement with the experimental results.Especially,the maximum sensitivity S=1144.07407 nm/RIU can be realized for glucose concentration variation from 0.3 to 0.4mol/L.There is obvious local electric field enhancement on the surface of Ag NPs.（3）A multilayer structure model,consisting of a MXene layer,a polymethyl methacrylate（PMMA）layer and silver nanoparticles（Ag NPs）on indium tin oxide（ITO）substrate,is established for investigating its optical absorption properties.The results exhibit that the proposed plasmonic structure shows outstanding broadband and wide-angle absorption,which was investigated through FDTD and experimental methods.Especially,the simulated data show well agreement with the experimental data.The results indicate that the absorption increases as the thickness of MXene layer varies from 180 nm to 650 nm,when the PMMA layer and Ag NPs were absent.After adding the PMMA layer and noble Ag NPs,ultrahigh wide-angle absorption was realized,as the angle of incidence varies from 0°to 60°.Moreover,the maximal absorption can reach up to 0.99 from visible to near-infrared region,and the whole value of absorption is higher than 0.93,which is owing to the obvious localized surface plasmon resonance（LSPR）generated on the surface of MXene layer and Ag NPs.And there is the obvious electric field enhancement on the surface of MXene and Ag NPs.