大面积图案化电场增强薄膜的设计及制备研究  

Design and Preparation of Large-Area Patterned Electric Field Enhanced Films

作　　者：孙伟 洪瑞金[1] 陶春先[1] 张大伟[1] Sun Wei;Hong Ruijin;Tao Chunxian;Zhang Dawei(School of Optical-Electronical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《中国激光》2023年第23期137-142,共6页Chinese Journal of Lasers

基　　金：国家自然科学基金(61775141,62075133,62275159)。

摘　　要：采用有限时域差分(FDTD)法仿真了不同闪耀光栅结构上的银(Ag)薄膜模型。在633 nm的激发光下,闪耀光栅上周期为1/1200 mm、厚度为15 nm的Ag薄膜模型产生了较强的局域表面等离子体共振(LSPR)效应。利用机械刻划工艺和电子束蒸发镀膜工艺成功制备了这种Ag光栅薄膜,从而大幅降低了图案化电场增强薄膜的制备成本和难度。利用该电场增强Ag薄膜,基于表面增强拉曼散射(SERS),对亚甲基蓝染料进行检测,SERS信号强度增强,与FDTD仿真结果吻合。同时,基底不同位置处的主要特征峰强度的相对标准偏差(RSD)值都小于17%,薄膜表现出良好的均匀性和再现性。Objective Currently,there are various technologies for controlling the electric field using the micro-nano structure of noble metal films,including electron beam lithography(EBL)and focused ion beam(FIB)etching.Most of these processing methods are complicated,with limited processing areas and high costs.These limitations significantly restrict the development of photoelectric functional films with electric field enhancement characteristics.According to current theories,the enhancement mechanism of surfaceenhanced Raman scattering(SERS)technology can be divided into electromagnetic enhancement mechanism(EM)and chemical enhancement mechanism(CM).Compared to CM,EM generally exhibits stronger increases in the Raman scattering signals.Therefore,it is important to develop EM-based SERS substrates.The enhancement of the electromagnetic field mainly originates from the local surface plasmon resonance(LSPR)of the metal nanoparticles,which is independent of the adsorbed molecules and is an inherent property of metal nanoparticles.Therefore,classical electronic dynamics methods such as the finite difference time domain(FDTD)method can be used to describe the electromagnetic field.The purpose of this study is to develop a large-area,low-cost,and reproducible SERS substrate using FDTD simulations combined with mechanical grating ruling and electron beam evaporation deposition.Methods In this study,Silver(Ag)films with different blazed grating structures are simulated using FDTD method.The LSPR of the Ag films with blazed grating structures is significantly enhanced by adjusting the period.Under excitation at 633 nm,we find that Ag films with a grating period of 1/1200 mm generate a significant LSPR effect.Large-area electric-field-enhanced Ag grating films that can be produced in batches are realized using a mechanical grating ruling process and electron beam evaporation deposition.We successfully apply this electric field-enhanced Ag film to SERS to detect methylene blue dye.The Ag grating films significantly enhance the SER

关 键 词：薄膜 局域表面等离子体共振 有限时域差分法 金属薄膜 闪耀光栅 表面增强拉曼散射 

分 类 号：O436[机械工程—光学工程]