我們利用高解析度的角解析光電子能譜(ARPES)與低能量電子繞射(LEED)來研究雙層鍺烯在Ag(111)上的能帶結構和在有雙層鍺烯結構的Ag(111)單晶上生長較厚的鉛薄膜。
我們成功在Ag(111)上形成並排鉛層的AB雙層鍺烯結構。其測量到的能帶兩個特徵與密度泛函理論(Density functional theory)相符。而其特性與光電子能量的關係可以透露其二維的特性。至於生長較厚的鉛薄膜於雙層鍺烯上時，我嘗試在-188 ◦C的溫度下再蒸鍍1-ML鉛在已覆蓋單層鉛薄膜的雙層鍺烯上。從LEED繞射圖上無法觀測到清楚的圖案，此表示無法生長更厚的鉛層。而後退火至室溫時，再次形成單層鉛。分析單層鉛於雙層鍺烯的LEED圖，指出鉛層具有多個不同晶格常數與角度的區域，因此無法再向上形成更厚的鉛薄膜。

We used high-resolution angled-resolved photoemission spectroscopy (ARPES) and low-energy electron diffraction (LEED) to study the energy band structures of bilayer germanene on Ag(111) and the growth of a thicker free-standing Pb film on a bilayer germanene on Ag (111). We successfully grew a AB-stacked bilayer germanene with a side-by-side Pb layer on Ag(111). Two features of energy band structures measured match those derived from the density function theory. The photon-energy dependence of these two features were investigated, revealing their 2-dimentional character. As for growing a thicker Pb layer on top of the bilayer germanene, I tried to deposit extra 1-ML Pb onto the bilayer germanene covered with a monatomic Pb layer at －188 ◦C. LEED showed no any clear pattern, indicating that growing a thicker Pb layer is impossible. Subsequent mild annealing to room temperature led to the phase of the monatomic Pb layer again. Detailed analysis of the LEED pattern of the monatomic Pb layer on bilayer germanene indicated multiple Pb domains of different lattice constants and orientations. Therefore, it is unlikely to grow a thicker Pb layer on such a strained template.

摘要
Acknowledgements
1前言----------------------------------------------------------1
1.1動機--------------------------------------------------------1
1.2目標--------------------------------------------------------2
2基礎理論------------------------------------------------------3
2.1晶格--------------------------------------------------------3
2.1.1晶體結構--------------------------------------------------3
2.1.2倒晶格----------------------------------------------------6
2.1.3電子能帶結構-----------------------------------------------9
2.2光電子能譜--------------------------------------------------10
3儀器介紹------------------------------------------------------15
3.1超高真空----------------------------------------------------15
3.2蒸鍍-------------------------------------------------------17
3.3濺鍍(sputter)----------------------------------------------17
3.4光源-------------------------------------------------------18
3.4.1氦燈(Helium Lamp)----------------------------------------18
3.4.2同步輻射光------------------------------------------------20
3.5低能量電子繞射儀(Low energy electron diffraction,LEED)-------21
3.6角解析光電子能譜(Angle resolved photoemission spectroscopy,ARPES)-23
4生長雙層鍺在Ag(111)上--------------------------------------------27
4.1樣品製備----------------------------------------------------27
4.2生長雙層鍺烯於Ag(111)上--------------------------------------28
4.3雙層鍺實驗結果分析-------------------------------------------33
5生長鉛薄膜於雙層鍺烯/Ag(111)上----------------------------------39
5.1生長較厚的雙層鍺烯於Ag(111)上---------------------------------39
5.2生長較厚鉛於雙層鍺烯於Ag(111)上-------------------------------44
5.3生長較厚鉛薄膜於雙層鍺烯於Ag(111)上結果分析--------------------47
6結論----------------------------------------------------------49
References-----------------------------------------------------51

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