銀奈米柱陣列薄膜之製鍍與非均向光學特性探討

The Fabrication and Anisotropic Optical Properties of an Aligned Silver Nanorod Array

許文龍(Wen-lung Hus)

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(2008年)

摘要

斜向沈積之金屬薄膜具有奈米柱狀結構，這些獨特的微觀柱狀結構因此擁有特別的光學現象。
本文探討平行於薄膜沈積平面之偏振光 (p-polarization) 與垂直於薄膜沈積平面之偏振光 (s-polarization)，正向入射在銀奈米柱陣列薄膜上其透射率隨波長的變化，且量測出來的p偏振光與s偏振光之透射率差異甚大，此斜向沈積之金屬薄膜可做為偏振片之光學元件；且當偏振光以不同的角度入射在銀奈米柱陣列薄膜上，s偏振光與p偏振光之透射率具有對稱與不對稱性的光學特性。
利用斜向角沈積法製鍍幾個不同傾角的銀奈米柱陣列薄膜，由生物型掃描式顯微鏡可觀察柱狀結構的生長情形；通常柱狀傾角都會小於沈積角，而這之間的關係可由兩經驗公式來表示。另外，我們也利用橢圓儀量測技術來量測銀奈米柱陣列的雙折射率差。

關鍵字

銀奈米粒子 ； 奈米柱陣列 ； 電漿共振

並列摘要

Obliquely deposited metal thin films with fabricated microscopic columnar structures and measured their special optical properties.
This work presents the different transmittances of the films for p-polarization (the direction of the incident electric field that is almost parallel to the major long axis of the nanorods) and s-polarization (the direction of the incident field that is perpendicular to the long axis of the nanorods) for normally incidence on the Ag nanorod array. Adding a isotropic Ag film will improve the extinction ration of the Ag nanorod array to be a polarizer. The asymmetric transmittance angular spectrum is also observed.
The Ag nanorod array is deposited at various deposition angles, therefore relation between columnar angle and deposition angle are built based on two different empirical rules: tangent rule and cosine rule. On the other hand, the enhanced birefringence of the Ag nanorod array is also measured by modified ellipsometric measurements.

並列關鍵字

Ag nanoparticle ； nanorod array ； plasmon resonance

參考文獻

[1] G. W. Mbise, D. Le Bellac, G. A. Niklasson, and C. G. Granqvist, "Angular selective window coatings: theory and experiments", J. Phys. D, vol. 30, pp. 2103-2122, 1997.

[2] T. Otiti, G.A. Niklasson, P. Svedlindh, C.G. Granqvist, "Anisotropic optical, magnetic, and electrical properties of obliquely evaporated Ni films", Thin Solid Film, vol. 307, pp. 245-249, 1997.

[3] Ian Hodgkinson, Sarah Cloughley, Qi HongWu, and Samer Kassam, "Anisotropic scatter patterns and anomalous birefringence of obliquely deposited cerium oxide films", Applied Optics, vol. 35, pp. 5563-5568, 1996.

[4] K. Robbie, M. J. Brett, A. Lakhtakia, "First thin film realization of a helicoidal bianisotropic medium", J. Vac. Sci. Technol., vol. 13, pp. 2991-2993, 1995.

[5] Russell Messiel, Vijayakumar C, Venugop M, Paul Sunal D, "Origin and evolution of sculptured thin films", J. Vac. Sci. Technol. vol. 18, pp. 1538-1545, 2000.