三溴化鉻(CrBr3)作為二維鐵磁半導體材料在電子自旋器件有很大的潛力，利用光學顯微鏡觀察其外觀，以場發射掃描式電子顯微鏡進行表面觀測確認其材料具有層狀結構並屬於二維材料，利用能量散射X射線譜研究此固態材料的元素為鉻和溴組成，並使用X射線光電子能譜儀確認其鍵結狀態與分子組成，X射線繞射儀與穿透式電子顯微鏡觀察其原子的排列型態與區域衍射型態去確認其屬於六方晶系，接著使用偏振拉曼光譜儀分析其晶格結構的兩種震動性質發現A1g振動模式會因為偏振角的改變，峰值會明顯受到抑制，並改變樣品方向取樣角度發現拉曼訊號會因為晶格結構的關係產生偏振，並發現偏振對於樣品的取向可能是光同向性的。選擇量測特定角度低溫下的A1g偏振拉曼峰值會向右偏移且強度會降低。

Chromium tribromide (CrBr3) is a two-dimensional ferromagnetic semiconductor material that has great potential in spintronic devices. The flakes of 2D CrBr3 are observed and characterized using various analytical proficiencies. The 2D layered nature of the flakes is confirmed using optical and electron microscopy. The chemical purity and stoichiometry of the CrBr3 flakes is confirmed qualitatively and quantitatively using an energy dispersive X-ray spectrometer and X-ray photoelectron spectrometer, respectively. The hexagonal crystal structure having space group P3 of the CrBr3 flakes is confirmed using the X-ray diffractometry and transmission electron microscope. The phonons involved in CrBr3 flakes is studied using polarized-Raman spectroscopy. The 2D CrBr3 consists of Eg and A1g vibration modes. The crystal orientation-dependent lattice vibrations and degree of polarization are observed using the A1g vibration modes. We find that the polarization is isotropic to the orientation of the samples, however, the degree of polarization is anisotropic property of 2D CrBr3 single crystal. The lattice vibrations of A1g at 80 K show a significant reduction in the degree of polarization at the polarization angle.

摘要
Abstract
目錄
圖目錄
第一章 文獻回顧與導論　　 1
1.1　二維材料　　 1
1.2　三鹵化鉻　　 2
1.3　二維材料的光偏振性質　　 3
1.4　研究動機　　 6
第二章 製備與分析儀器技術　　 7
2.1　實驗用儀器與樣品材料　　 7
2.1.1　樣品製備與保存環境　　 7
2.1.2　實驗材料　　 8
2.2　場發射掃描式電子顯微鏡 (FESEM)　　 8
2.3　能量散射X射線光譜儀 (EDS)　　 10
2.4　X射線光電子能譜儀 (XPS)　　 10
2.5　X射線繞射儀 (XRD)　　 12
2.6　穿透式電子顯微鏡 (TEM)　　 13
2.7　拉曼光譜 (Raman spectroscopy)　　 14
2.7.1　偏振拉曼光譜 (polarized Raman spectroscopy)　　 15
第三章　實驗結果與分析　　 17
3.1　光學顯微鏡和場發射電子顯微鏡　　 17
3.2　能量散射X射線光譜儀分析　　 18
3.3　X射線光電子能譜數據分析　　 19
3.4　X射線繞射數據與分析　　 20
3.5　穿透式電子顯微鏡數據分析　　 21
3.6　拉曼光譜數據分析　　 22
3.6.1　偏振拉曼光譜數據分析　　 23
3.6.2　低溫偏振拉曼光譜數據分析　　 28
第四章　結論　　 31
參考文獻　　 33

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