我們研究TTC及PFT沉積於平整銀薄膜的系統，藉由角解析光電子能譜來觀察量子井態以及真空能階的偏移，探討有機薄膜與金屬薄膜的介面現象。隨著沉積有機分子於銀薄膜表面，改變了有機薄膜與銀薄膜介面，因此量子井態的能量位置會隨著有機薄膜的厚度而改變。我們藉由觀察真空能階的變化來了解介面現象，在我們研究的系統中，TTC與PFT沉積於銀薄膜表面真空能階偏移方向不同，我們認為造成的原因為兩分子的電子親和力不同。我們利用波爾-索莫菲量子化定則以及鏡像位能模型來求得有機薄膜的介電常數，我們比較單層PFT與TTC薄膜的介電常數發現PFT薄膜的介電常數有受到屏蔽效應的影響。

We have studied the system of TTC and PFT on uniform silver thin films. The interfacial properties between the organic molecules and the uniform silver thin film can be probed by the use of the angle-resolved photoemission spectroscopy (ARPES). After the deposition of the organic molecules onto the silver surface, we found the change of energy position of the QWS and the change of the vacuum level, and these phenomena can be attributed to the result of the change of the interfacial potential at the organic/metal interface. From our results, we found that the vacuum level shift toward opposite directions and these results might come from the difference of the electron affinity of TTC and the PFT. By introducing the Bohr-Sommerfeld quantization rule and the modified image potential model, the dielectric constant of the organic thin film can be extracted.

摘要 I

ABSTRACT II

致謝 III



1.導論 1

2.基礎理論 3

2.1表面態 3
2.2 量子井態 5
2.3 鏡像位能模型 8
2.4有機材料的電子結構 11
2.5介面電子結構 13
2.6 有機材料 17
2.6.1 Tetratetracontane (TTC) 分子 17
2.6.2 Perfluorotetracosane (PFT)分子 19

3.實驗儀器與原理 22

3.1超高真空 24
3.2 離子濺射槍 (sputter gun) 26
3.3 蒸鍍槍 (Knudsen cell) 27
3.4 低能量電子繞射儀 (LEED) 28
3.5 同步輻射光源 31
3.6　光電子能譜 33
3.6.1　簡介 33
3.6.2 光電效應理論模型 35
3.6.3　角解析光電子能譜 39
3.6.4　電子能量分析儀 42
3.6.5 接收模式 45
3.6.6 解析度 46

4.樣品製備與分析方法 47

4.1樣品製備 47
4.1.1清潔鍺(111)表面 47
4.1.2成長銀薄膜與沉積有機薄膜 49
4.2功函數量測與分析 52
4.3計算有機薄膜介電常數 55

5.實驗結果 58

5.1真空能階偏移(Vacuum Level Shift) 58
5.1.1 TTC分子/銀薄膜/鍺(111) 58
5.1.2 PFT分子/銀薄膜/鍺(111) 61
5.2 有機薄膜的介電常數 65
5.2.1 TTC薄膜介電常數 65
5.2.2 PFT薄膜介電常數 68

6.總結 71

參考資料 73

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