本論文主要研究在Ag(111)基底上有Bi原子存在的情況下，再生長鍺烯。Bi原子沉積在Ag(111)單晶基底上，根據Bi鍍量的不同，會形成Ag2Bi表面合金-(√3×√3)R30◦、Bi/Ag(111)-(p×√3)和Bi(110)/Ag(111)。利用低能量電子繞射(low energy electron diffraction, LEED)和角解析光電子能譜(angle-resolved photoemission spectroscopy, ARPES)，我們研究在兩種不同Bi/Ag(111)表面上鍍Ge的晶格和電子結構的變化:1. Ag2Bi表面合金-(√3×√3)R30◦單獨合金。2. Ag2Bi合金表面-(√3×√3)R30◦與Bi/Ag(111)-(p×√3)共存。對於前者，我們發現到Ag2Bi表面合金發生去合金為Bi/Ag(111)-(p×√3)結構，且與準獨立相(QP)鍺烯並排生長。代表在垂直於√3長度方向上的p值晶格常數會隨著Ge鍍量的增加而縮小。對於後者，結構上仍產生去合金現象，但同時出現的是條紋相(SP)鍺烯，並非準獨立相(QP)鍺烯，而隨著Ge鍍量的增加，p值晶格常數甚至縮小到比第一部分更小。
Ag2Bi表面合金-(√3×√3)R30◦和Bi/Ag(111)-(p×√3)的表面能帶結構與Ge-3d和Bi-5d核能階態變化，均與兩部分實驗中LEED結果結論一致。以及建構在Ag(111)基底上的Ag2Bi表面合金-(√3×√3)R30◦和Bi/Ag(111)-(p×√3)之間所對應的晶格模型，用以解釋第二部分實驗中所產生的有趣結構。

The purpose of the project in this thesis is to study the growth of germanene on Ag(111) with the presence of Bi atoms. Deposition of Bi on Ag(111) single-crystal substrate results in the formation of Ag2Bi alloy-(√3×√3)R30◦ surface, Bi/Ag(111)-(p×√3), and Bi(110)/Ag(111) with increasing coverage of Bi. Using low energy electron diffraction (LEED) and angle-resolved photoemission spectroscopy (ARPES), we studied the evolution of lattice and electronic structures for Ge deposition on two different Bi/Ag(111) surfaces: 1. Ag2Bi-(√3×√3)R30◦ surface alloy alone. 2. Ag2Bi surface alloy-(√3×√3)R30◦ coexisting with Bi/Ag(111)-(p×√3). For the former, we found Ag2Bi surface alloy was de-alloyed to Bi/Ag(111)-(p×√3) superstructure and quasi-freestanding phase (QP) germanene forms side-by-side. The p value indicating the lattice constant in the direction perpendicular to that of √3 reduces with the increasing Ge coverage. For the latter, the de-alloying still occurs while striped-phase (SP) germanene shows up instead of QP. The p value reduces even to a smaller value than that of case 1 with the increasing Ge coverage.
Surface-state band structures of Ag2Bi surface alloy-(√3×√3)R30◦ and Bi/Ag(111)-(p×√3) as well as Ge-3d and Bi-5d core-level states all behave consistent to the conclusions drawn from the LEED results of these two cases. An lattice model for the commensurate boundary between Ag2Bi surface alloy-(√3×√3)R30◦ and Bi/Ag(111)-(p×√3) on Ag(111) is constructed to explain the interesting behavior of case 2.

Abstract (Chinese) I
Abstract II
Acknowledgements III
Contents IV
List of Figures VII
List of Tables XV
1 基礎理論 1
1.1 前言......................................................1
1.2 真空......................................................3
1.2.1 平均自由徑..............................................4
1.2.2 真空區分................................................4
1.3 晶體結構..................................................5
1.3.1 晶胞(cell) .............................................6
1.3.2 布拉菲晶格(Bravais lattice)..............................7
1.3.3 米勒指標(miller index)與晶格面............................7
1.3.4 倒晶格..................................................10
1.3.5 布里淵區(Brillouin zone)................................11
1.3.6 Wood’s notation.........................................11
1.3.7 勞厄方程式(Laue equation)................................13
1.3.8 愛德華球體(Ewald sphere).................................14
1.4 光電子能譜(Photoemission Spectroscopy, PES)................15
1.4.1 光電效應.................................................15
1.4.2 三步驟模型(three step model).............................16
1.4.3 角解析光電子能譜(Angle Resolved Photoemission
Spectroscopy, ARPES)..........................................17
2 實驗儀器與原理 19
2.1 超高真空系統...............................................19
2.1.1 真空腔體實驗環境.........................................20
2.2 真空幫浦...................................................21
2.2.1 乾式渦卷幫浦(Dry scroll pump)............................22
2.2.2 渦輪分子幫浦(Turbo molecular pump).......................22
2.2.3 離子幫浦(Ion pump).......................................24
2.2.4 鈦昇華幫浦(Titan sublimate pump) ........................25
2.3 低能量電子繞射儀(Low Energy Electron Diffraction, LEED).....25
2.4 蒸鍍槍(Kundsen cell evaporator)............................27
2.5 濺鍍槍(sputter gun)........................................28
2.6 殘餘氣體分析儀(Residual Gas Analysis, RGA)..................29
2.7 光源.......................................................30
2.7.1 氦燈(Helium lamp)........................................30
2.7.2 同步輻射光源..............................................31
2.8 角解析光電子能譜與能量分析儀.................................33
3 在Ag(111)上蒸鍍成長不同金屬原子 35
3.1 蒸鍍Ge原子在Ag(111)上.......................................35
3.1.1 鍺銀合金(Ag2Ge alloy).....................................35
3.1.2 條紋相(Striped Phase, SP)鍺烯.............................36
3.1.3 準獨立相(Quasi-freestanding Phase, QP)鍺烯................37
3.2 利用外來原子調控Ag(111)上鍺烯結構............................39
3.3 交換Ag(111)上蒸鍍Ge、Pb原子的順序............................42
3.4 蒸鍍Bi原子在Ag(111)上.......................................43
3.4.1 鉍銀合金(Ag2Bi alloy)-(√3×√3)R30◦結構.....................43
3.4.2 去合金過程-(p×√3)結構.....................................44
3.4.3 Bi(110)薄膜覆蓋層.........................................45
4 實驗數據與分析 49
4.1 實驗動機....................................................49
4.2 製備乾淨Ag(111)單晶基底樣品..................................50
4.3 實驗內容....................................................51
4.3.1 鍍相對薄的鉍薄膜，再退火加熱基板，鍍鍺在鉍銀合金(√3×√3)R30◦
上..............................................................51
4.3.2 鍍相對厚的鉍薄膜，再退火加熱基板，鍍鍺在鉍銀去合金過程(p×√3)
上..............................................................61
4.4 實驗討論....................................................71
5 結論 72
Bibliography 73

1. 陳亭宇. 利用蒸鍍沉積外來原子調控準獨立鍺烯的形成. 國立清華大學物理所碩士論文，新竹市, 取自https://hdl.handle.net/11296/q2meb4 (2018).
2. 許育翔. 在表面合金基底上成長雙層鍺烯. 國立清華大學物理所碩士論文，新竹市, 取自https://hdl.handle.net/11296/dt35hh (2021).
3. McLeod, I., Dhanak, V., Matilainen, A., Lahti, M., Pussi, K. & Zhang, K. Structure determination of the p3× 3R30Bi–Ag(111) surface alloy using LEED I–V and DFT analyses. Surface science 604, 1395–1399 (2010).
4. Zhang, K., McLeod, I., Lahti, M., Pussi, K. & Dhanak, V. The evolution of the electronic structure at the Bi/Ag(111) interface studied using photoemission spectroscopy. Journal of Physics: Condensed Matter 24, 435502 (2012).
5. Bihlmayer, G., Blugel, S. & Chulkov, E. V. Enhanced Rashba spin orbit splitting in Bi/ Ag (111) and Pb/ Ag (111) surface alloys from first principles. Physical Review B 75, 195414 (2007).
6. Oura, K., Lifshits, V., Saranin, A., Zotov, A. & Katayama, M. Surface science: an introduction (Springer Science & Business Media, 2013).
7. Kittel, C. & McEuen, P. Introduction to solid state physics (John Wiley & Sons, 2018).
8. Luth, H. Solid surfaces, interfaces and thin films (Springer,2001).
9. Hufner, S. Photoelectron spectroscopy: principles and applications(Springer Science & Business Media, 2013).
10. 伍秀菁，汪若文，林美吟. 真空技術與應用(行政院國家科學委員會精密儀器發展中心, 2001).
11. 蘇青森.真空技術精華(台灣五南圖書出版股份有限公司, 2015).
12. Effusion Cell EF 40C1 User Manual (PREVAC).
13. Ion Source IQE 11/35 User Manual (SPECS).
14. Modles RGA100,RGA200,and RGA300 Residual Gas Analyzer (SRS).
15. Very High Intensity UV Lamp and UVS 300-A power Supply User Manual Version1.2(SPECS).
16. 同步加速器光源簡介. NSRRC, https://www.nsrrc.org.tw/chinese/lightsource.aspxline (accessed Nov. 2023).
17. SCIENTA R3000 User Manual (VG SCIENTA).
18. Chen, T.-Y., Mikolas, D., Chiniwar, S., Huang, A., Lin, C.-H., Cheng, C.-M., Mou, C.-Y., Jeng, H.-T., Pai, W. W. & Tang, S.-J. Germanene structure enhancement by adjacent insoluble domains of lead. Physical Review Research 3, 033138 (2021).
19. Bian, G.,Wang, X., Miller, T. & Chiang, T.-C. Origin of giant Rashba spin splitting in Bi/Ag surface alloys. Physical Review B 88, 085427 (2013).
20. Zhang, K., McLeod, I., Lu, Y., Dhanak, V., Matilainen, A., Lahti, M., Pussi, K., Egdell, R., Wang, X.-S., Wee, A., et al. Observation of a surface alloying-todealloying transition during growth of Bi on Ag (111). Physical Review B 83, 235418 (2011).
21. Lu, Y., Xu,W., Zeng, M., Yao, G., Shen, L., Yang, M., Luo, Z., Pan, F.,Wu, K., Das, T., et al. Topological properties determined by atomic buckling in self-assembled ultrathin Bi (110). Nano letters 15, 80–87 (2015).
22. Kecik, D., O¨ zc¸elik, V., Durgun, E. & Ciraci, S. Structure dependent optoelectronic properties of monolayer antimonene, bismuthene and their binary compound. Physical Chemistry Chemical Physics 21, 7907–7917 (2019).