金屬、介電值三維八邊形螺旋結構之製作與吸收特性分析

Metal-Dielectric Three Dimensional Helical Octagon Structure: Fabrication and Analysis of Absorption Property

陳建圻(Chien-Chi Chen)

指導教授 ： 任貽均

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2012年)

摘要

近年來由於超穎材料日漸往三維的方向發展，廣波域以及廣角度吸收一直是大家所追求的目標。本篇論文利用電子槍蒸鍍系統搭配斜向角度沉積法與交錯沉積技術製鍍不同尺寸、厚度之介電值混合金屬的三維八邊形奈米結構來達到廣波域以及廣角度吸收。樣品以SEM觀察其表面與截面的結構，可看出其八邊形為一類似螺旋型的結構且金屬的部分表面圖呈現月牙形狀。再藉由對SEM的圖片進行影像處理可以計算出實際結構的厚度。本實驗製鍍了1週期、1.5週期、2週期的二氧化矽混合鋁和二氧化矽混合銀的三維八邊形奈米結構。
光學量測部分，將製鍍完成的各個尺寸的八邊形結構量測p偏振態和s偏振態穿透與反射的可見光光譜，量測角度從0°~75°。從量測的結果得知二氧化矽混合鋁兩週期八邊形結構在可見光波段0°~75°入射的p偏極態與s偏極態吸收平均達9成以上。為了瞭解其吸收特性，利用有限時域差分法套裝軟體定性模擬電場在鋁月牙結構中的共振行為以及利用商業軟體”Wvase 32”凝合二氧化矽混合鋁兩週期八邊形結構的等效折射率。由於本實驗為一類似螺旋狀的結構，文章最後利用橢偏儀量測了橢圓參數並探討其旋光性

關鍵字

超穎材料 ； 交錯沉積技術 ； 八邊形螺旋結構 ； 吸收

並列摘要

Due to the development of metamaterials growing to three-dimensional structure, broadband and wide-angle absorption is a goal for every researcher. In this paper, we use the electron beam evaporation with glancing angle deposition and bideposition technology to fabricate dielectric-metal composite three dimensional octagon nanostructure for different size and thickness which can reach the broadband and wide-angle absorption. We use SEM to observe samples’ top view and cross section is similar to helical and the metal part looks like crescent moon. The film’s thickness can be known with the cross section. The 1, 1.5, 2 period SiO2-Al and SiO2-Ag composite three dimensional octagon nanostructure were fabricated.
In the optical measurement, we measured every size of the sample with transmittance and reflectance visible spectrum for p(s) polarization, the incident angle is 0°~75°. The result show that 2 period SiO2-Al octagon helical structure exhibited high absorption of average above 90% at visible light and incident angle 0°~75° for p polarization and s polarization. In addition, we used FDTD to simulate the crescent aluminum’s electric field resonance to realize the samples’ property of absorption and use the commercial software “Wavse32” to fit the effective refractive index of 2 period SiO2-Al octagon helical structure. Finally, the circular property of 2 period SiO2-Al octagon helical was observed by measure the ellipsometric parameters (Ψ and Δ).

並列關鍵字

metamaterial ； bideposition ； helical octagon structure ； absorption

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