运用有效介质理论模拟银薄膜的光学特性

Simulation of the Optical Properties of Silver Thin Films by Effective Medium Theory

采用金属真空热蒸发技术制备了不同厚度的银薄膜,并用UV-2500型双光束分光光度计对其光学性质进行了表征。应用Maxwell-Garnett和Bruggeman理论模拟了薄膜的折射率、消光系数、透射率以及光吸收系数随波长变化的曲线,并与实验结果进行了比较,发现消光系数的峰位、透射率曲线的谷位及其移动趋势与实验结果一致,同时对实验结果与模拟结果存在差异的原因进行了分析。

Silver thin films with different thicknesses were produced by metal vacuum thermal evaporation technique. Their optical properties were characterized by UV-2500 double-beam spectrophotometer. The refractive index, extinction coefficient, transmittance, as well as the absorption coefficient of the sil- ver films were simulated by using Maxwell-Garnett （MG） and Bruggeman （BG） theory. The results show that the peak positions of extinction coefficient curves, the dip positions of transmittance curves, and their corresponding shift trends are agree well with the experimental data. At the same time, the reasons that may be responsible for the difference between experimental results and calculated results were analyzed.