Research On Control Luminescence Properties Of CsPbBr₃ Perovskite By Aluminum Metasurface

With the development of miniaturization and integration of optoelectronic devices,the metasurface with sub-wavelength level has become a new hot issue in academia.The metasurface is processed by micro-nano processing technology to make it have unique functions.If the incident light matches the overall vibration frequency of the noble metal nanoparticles,the nanoparticles absorb the photon energy.Then,Localized surface plasmon resonance will occur which enhances the intensity of the local electric field.And metasurface can be applied to detection,sensing,fluorescence enhancement.In the past,the metasurface research on metals is mainly focused on gold and silver.However,gold will strongly absorb photon energy in the visible range,silver is unstable in the air,and their cost is high.The plasmon resonance of aluminum can cover the entire visible light band and even the ultraviolet band.Combined with its advantages of nature abundance and low-cost,aluminum has become a promising material.Research on perovskite lasers is also very extensive.Patterning semiconductor lasers is an effective way to control light emission and absorption.However,many patterning techniques,such as electron beam lithography and traditional stripping processes cannot be applied to perovskite because of its instability.Therefore,the structure of aluminum metasurface to achieve local electric field enhancement was designed.Aluminum metasurface was applied to perovskite to regulate its photoluminescence.Because high-cost gold and silver can't work in the near-ultraviolet band,aluminum metasurface with local field enhancement was designed,which can work in near-ultraviolet band.And the preparation process of metasurface was studied.The period and spacing of the structure and the thickness of each layer were simulated by COMSOL electromagnetic field numerical simulation software,and the influence of each parameter on the resonance was analyzed.The parameters were studied the effect on resonance to ensure work in near-ultraviolet band and the electric field enhancement factor is maximized.The parameters of each layer of the structure were determined and the preparation of aluminum metasurface were also be explored.In order to solve the lack of top-down processing preparation in perovskite,a simple maskless coating preparation was used on perovskite.After the preparation,aluminum metasurface on perovskite can regulate the laser intensity and threshold of perovskite.By controlling the evaporation coating time and ensuring the low coating rate,aluminum is deposited on the surface of the perovskite microrod.The optical path was used to measure the spectrum of perovskite before and after deposition.It was found in the experiment that the perovskite after deposition at a certain time and rate formed relatively uniform aluminum particles on the surface.At this time,it can be regarded as a metasurface with a certain arrangement,and the laser intensity was increased by an order of magnitude.The threshold was reduced by approximately 20%.On this basis,the coated perovskite structure was numerically modeled using COMSOL software,and its resonance absorption spectrum was calculated to provide a certain explanation for the spectral change of the perovskite after deposition.