Fabrication And Optical Properties Of Ordered Arrays Of Metal Nanotubes

The two-dimensional periodic structures composed of metal and dielectric materials have unique surface plasmon characteristics,which have wide application prospects in the fields of biomedicine,chemical sensing,information transmission,ultra-high-resolution imaging and energy.Because of the traditional manufacturing technology is still restricted by manufacturing efficiency and cost,a low-cost and efficient method,nanosphere printing,has been developed.The current research trend is to use this method to prepare metal periodic nanostructures with novel physical phenomena,which will improve the performance of traditional device and implementation of new functional devices.The following is the main work of this paper:A new method for preparing a large-area,ordered and compact metal nanotubes in a controlled and low-cost manner using a traditional semiconductor manufacturing method is proposed,that is,using self-assembled PS microspheres as a mask,through etching,coating and other processes.The finite difference time domain method(FDTD)was used to simulate the reflection spectrum,electric field distribution and charge density of the nanotube,the simulation results show that inspired of BW-SPP modes with different wavelengths in the tube and coupled cavity mode,and these modes are largely dependent on the geometric parameters of the tube.By adjusting the geometric size of the structure,the wavelengths corresponding to the energy of the surface plasmon mode formed in the cavity are continuously adjustable in the visible and infrared bands.The experimental samples were characterized and tested,and the simulation results were found to be consistent with the experimental results.The effects of structural parameters and Ag film thickness on the reflection spectrum of the nanotubes were studied.And the relationship between the reflection spectrum of the structure and the incidence Angle and polarization was also tested.In addition,a large-area ordered non-compact cylindrical array can be obtained by using nanoring tube as a template,which has a strong gap plasma effect and is suitable for SERS substrates.A low-cost and high-quality ordered no-compact gold nanotube array is proposed,and the optical properties of the structure are studied and its filter property is explored.FDTD simulation calculations shows that under linear polarized light incident,multiple cylindrical surface plasmon resonances and gap surface plasmon resonances can be formed inside and outside the nanotubes,and the size of resonance wavelength is related to the parameters of the structure.According to the transmission spectrum,reflection spectrum and electric field distribution,the resonance mode of the plasmon on the cylindrical surface has a strong absorption ability,and most of the energy is lost in the tube cavity.By adjusting the parameters of the structure,it was found that the wavelength of the resonance modes could be adjusted within the range of 600 nm to 1800 nm.Then the parameters of the structure could be further optimized and combined to achieve the purpose of filtering in a larger range and more bands.The refractive index sensing performance of the structure is studied,and it is found that the structure has better resonance reflection phenomenon and higher sensitivity than traditional sensors.