在本論文的研究中，我嘗試在晶格結構為Ag(111)-√3×√3 R〖30〗^°的Ag_2 Pb表面合金上製作雙層鍺烯結構，且以低能量電子繞射(low-energy electron diffraction; LEED)和光電子能譜(Photoemission spectroscopy; PES)來研究晶格結構和電子能譜。在最初蒸鍍Ge原子時，我們發現在不同的退火條件下QP(Quai-freestanding phase)鍺烯能夠形成兩種組態，第一種是在特定角度範圍內有連續多個區域分布的情況，第二種為比較有序的QP鍺烯角度區域固定在相對Ag(111)-√3×√3 R〖30〗^°基底旋轉±3^°度。我們接著分別在這兩種結構上交替蒸鍍上Pb和Ge原子來製作雙層鍺烯結構。透過實驗我發現了雙層鍺烯能夠在前者上成形但在後者卻無法有效地形成結構。
透過檢視了QP鍺烯在Ag(111)上的HOC(higher-order-coincidence)點的密度，我們發現了分裂±3^°度的QP鍺烯在各種角度分布中是最穩定的，所以我們推斷當蒸鍍更多的Pb和Ge原子時，最初在Ag(111)上穩定的QP鍺烯會阻礙隨後的雙層鍺烯生長。與之相反，如果初始的QP鍺烯穩定性較差，例如在特定角度範圍內有連續多個區域分布的情況，在蒸鍍更多的Pb和Ge原子後，能夠更靈活地透過應變效應來進一步的演變為雙層鍺烯。

In the research work of this thesis, I attempted to grow bilayer germanene on the Ag2Pb alloy surface with the lattice structure Ag(111)- and investigated the resulting lattice and electronic structures by low-energy electron diffraction (LEED) and photoemission spectroscopy (PES). Upon initial Ge deposition, we found germanene of quasi-freestanding phase (QP) can form in two configurations, QP with multiple domains rotating continuously within a certain angle range, and more ordered QP with only two domains locked into 3 rotation with respect to Ag(111)- , depending on the annealing conditions. We then alternatively deposit Pb and Ge onto these two templates, respectively to form bilayer germanene. I discovered that bilayer germanene can form for the former but cannot for the latter.

By checking the density of higher-order-coincidence (HOC) points for QP germanene on Ag(111), we find QP with only two domains locked into 3 is most stable so we reason that the initial stable QP germanene on Ag(111) is against the subsequent growth to bilayer germanene when more Pb and Ge atoms are deposited. On the contrary, if the initial QP germanene is less sable such as the case of multiple domains rotating continuously within a certain angle range, it is more flexible to undergo strain effect to further evolve to bilayer germanene after depositing more Pb and Ge atoms.

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