中国激光, 2020, 47 (1): 0103001, 网络出版: 2020-01-09
脉冲激光改性金属纳米薄膜的等离子体特性 下载: 1761次
Pulsed-Laser-Modified Plasmon Properties of Metal Nanofilms
薄膜 激光辐照 金属薄膜 局域表面等离子体共振 表面增强拉曼散射 时域有限差分法 thin films laser irradiation metal films localized surface plasmon resonance surface-enhanced Raman scattering finite difference time domain method
摘要
在室温环境下,实验采用Nd∶YAG光纤脉冲激光器辐照银(Ag)、铜(Cu)、铝(Al)三种光滑连续的金属薄膜,制备出了对应的三种金属纳米颗粒薄膜。通过调节激光扫描速率可以实现三种金属纳米颗粒薄膜的局域表面等离子体共振(LSPR)波长和强度的调谐。其中,Ag纳米颗粒薄膜在可见光波段的等离子体吸收峰的波长和强度均表现出较宽的调谐范围,Cu纳米颗粒薄膜在可见光波段的等离子体吸收峰的波长和强度均表现较小的调谐范围,Al纳米颗粒薄膜在紫外光波段的等离子体吸收峰窄而尖锐,且LSPR波长调谐范围也较小。与激光辐照前的三种金属薄膜相比,激光辐照后生成的三种金属纳米颗粒薄膜出现了更强的表面增强拉曼散射信号。有限差分时域仿真模拟出的样品的电场强度分布与实验得到的表面增强拉曼散射结果一致。
Abstract
Three metal (Ag, Cu, and Al) nanoparticle (NP) films are obtained by irradiating a smooth and continuous metal film with a Nd∶YAG fiber pulsed laser at room temperature. The tunability of the wavelength and intensity of localized surface plasmon resonance (LSPR) of the three metal NP films is realized by varying laser scanning speeds. The wavelength and intensity of the plasmon absorption peak of Ag NP film in visible wavelength region show a wide tuning range, while the wavelength and intensity of the plasmon absorption peak of the Cu NP film exhibit a small tuning range in the visible wavelength region. Unlike Ag and Cu NP films, the Al NP film exhibits a narrow and sharp plasmon absorption peak in the ultraviolet wavelength region, and the wavelength tuning range of LSPR is also small. Further, the stronger surface-enhanced Raman scattering signals are observed in all three kinds of laser-irradiated metal NP films than in the deposited metal films before laser irradiation. The results of the finite difference time-domain simulation with respect to the electric-field intensity distributions of all samples show good agreement with the experimental results of surface-enhanced Raman scattering.
孙文峰, 洪瑞金, 陶春先, 张大伟. 脉冲激光改性金属纳米薄膜的等离子体特性[J]. 中国激光, 2020, 47(1): 0103001. Wenfeng Sun, Ruijin Hong, Chunxian Tao, Dawei Zhang. Pulsed-Laser-Modified Plasmon Properties of Metal Nanofilms[J]. Chinese Journal of Lasers, 2020, 47(1): 0103001.