- 學位論文
以熱退火控制金薄膜粗糙度提高表面增強拉曼散射效應
Using Thermal Annealing to Control the Gold Film Roughness to Improve Surface-Enhanced Raman Scattering Effect
摘要
本研究以熱蒸鍍和熱退火（Annealing）為主要的製作方式，不需使用任何化學方式即可在石英和矽基板上製成表面增強拉曼散射（Surface-enhanced Raman scattering；SERS）基材。經由熱蒸鍍的方式，可得到一個厚度可控的奈米級金薄膜，再使用不同溫度和不同氣體環境（Ar、N2、O2）以熱退火控制基板上金薄膜凝聚成奈米金島（Nano-Au-Islands；NAuI）的大小，用於探討SERS 的增強效果。 實驗中以電子顯微鏡（SEM）掃描樣品得到基板上的NAuI 形貌，能與原子力顯微鏡（AFM）相互對照，並以X-ray 光電子能譜儀（XPS）檢測基材表面Au 的能階情況，SERS 基材以Rhodamine 6G（R6G）作為探測分子判斷增強幅度，研究結果顯示，以AFM 計算出的平均粗糙度（Ra）可以做為SERS 強度的指標。SERS 基材以熱蒸鍍和熱退火的方式製備，可大量的生產，而熱退火時通入O2 可以更快形成NAuI ，即可在較短的時間與較低的溫度達到較高的Ra 。
並列摘要
This research aims to discuss the surface-enhanced Raman scattering-active (SERS) substrates made from quartz and silicon substrates by thermal evaporation and thermal annealing without any chemical treatment. We prepared thickness-controllable nanoscale gold films by thermal evaporation. The gold films were then annealed under different temperatures and gases (Ar, N2 and O2) enviroments. Through these methods we can control the size of the nano gold island (NAuI) on the substrates. The morphological evolution of the gold films upon the thermal annealing-induced dewetting was studied by using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) was used to detect the energy level of Au. Rhodamine 6G (R6G) was used as a probe molecule to determine the magnitude of the SERS enhancement. The result of this research shows that the roughness (Ra) calculated by AFM can be used to indicate the strength of SERS. The SERS substrates manufactured by thermal evaporation and thermal annealing are possible for mass-production. Thermal annealing-induced dewetting under oxygen can cause faster morphological evolution. Therefore a higher Ra can be reached at lower temperature.