The Simulation Of Localized Surface Plasmon Resonance Between Ag Nanostructure Arrays And Oxidized Silicon Nitride Films And Its Application On The Enhancement Of Luminescence Efficiency

The utilization of near filed enhancement of localized surface plasmon(LSP)from noble metal(Ag,Au)in nanoscale is an important approach to enhance the luminescence efficiency of semiconductor device.Here we focus on the research on the luminescence enhancement of Si-based a-SiN_x:O films by LSP coupling from ordered Ag nanoarrays with controllable-size.Through the simulation of scattering and absorption of LSP produced by hexagonal Ag nanoarrays with the radius of 25 nm,50 nm,75 nm and 100 nm embedded in the a-SiN_x:O films,we analyzed the coupling resonance between a-SiN_x:O films and hexagonal Ag nanoarrays with variable size and distance.It is found that the novel diameter of Ag nanoarrays in optimum coupling state is 25 nm.The near field enhancement and the dipole polarization mode under optimum LSP resonance of hexagonal Ag nanoarray and a-SiN_x:O films were calculated with excitation wavelength of 460 nm.The distribution of perpendicular radioactive space of LSP provides the optimum thickness of a-SiN_x:O films with strongest blue light emission.Polystyrene sphere lithography combined with laser annealing was used to fabricate Ag nanosphere-shell arrays with controllable size.For nanosphere-shell arrays with diameter of 300 nm,the enhancement of photoluminescence(PL)at 420 nm from a-SiN_x:O films reaches 40 folds.The analysis of temperature dependent PL and time resolved PL revealed that the internal quantum efficiency of a-SiN_x:O films is increased by 8%.For comparison with nanosphere-shell structure,we fabricated Ag nanoparticles by thermal annealing of Ag film.The average size of particles is 460 nm and 240 nm.After introduction of the two kinds of nanoparticle between Si substrate and a-SiN_x:O films,the PL at 470 nm from a-SiN_x:O films was enhanced by 2.7 folds and 4.1 folds.The calculated surface electric field intensity of Ag nanoparticles proves that the polarization is quadruple mode and PL enhancement of a-SiN_x:O films originates from the near field enhancement of LSP from Ag nanoparticles.The main research results and innovations are list as following:1?In order to investigate the resonance coupling between hexagonal nano Ag array and the a-SiN_x:O films,we employed COMSOL Multiphysics and FDTD Solution to simulate the scattering and absorption of hexagonal Ag nanoarrays with radius 25 nm,50 nm,75 nm and 100 nm embedded in a-SiN_x:O films.It is observed that the scattering and absorption peak red-shift from 460 to 630 nm with the radius increasing from 25 nm to 100 nm.And high order polarization mode like quadruple mode appears.Meanwhile the scattering and absorption Ag nanoparticles with various distance was also simulated.It is further confirmed that the optimum size of Ag nanoparticles for LSP resonance with blue PL from a-SiN_x:O films is 25 nm.The near field enhancement of hexagonal Ag nanoarrays with diameter of 25 nm was calculated under the excitation wavelength of 460 nm.It is found the dipole polarization mode is the result of bond coupling in bright mode under resonance.For hexagonal Ag nanoarrays with diameter of 25 nm,the calculated distribution of perpendicular radioactive intensity of LSP verifies that the optimum thickness of a-SiN_x:O films with strongest blue light emission is 30 nm.2?We adopt polystyrene sphere lithography combined with laser annealing to fabricate nanosphere-shell arrays with diameter of 170 nm,220 nm and 300 nm.By varing diameter,the LSPR wavelength can be tuned from violet to blue.The PL peak of a-SiN_x:O fabricated on the Si substrate with three kinds of nanosphere-shell arrays red shift from 380 nm to 420 nm.For nanosphere-shell arrays with diameter of 300 nm,the enhancement of photoluminescence(PL)at 420 nm from a-SiN_x:O films reaches 40 folds.The analysis of temperature dependent PL and time resolved PL reveals that the internal quantum efficiency of a-SiN_x:O films is increased by 8%.The calculated radiative intensity of nanosphere-shell by using FDTD indicates that the enhancement of electricfield is equal to that of PL.It is further confirmed that the enhanced PL from a-SiN_x:O films is related to the increased recombination rate induced by LSPR.Therefore,the internal quantum efficiency of a-SiN_x:O films is increased.