本論文主要是研究在氧化鋁基板(0001)上利用分子束磊晶系統成長Bi2Te3薄膜，在改變不同的成長條件下，藉由RHEED、AFM、XRD的量測分析。結果發現在成長溫度為330℃，flux_Te⁄flux_Bi =10~15時，我們可以成長出結晶性佳且具有表面平坦度高的Bi2Te3薄膜。在電性量測下，Bi2Te3薄膜的RT曲線在不同的溫度區間有不同的表現，與參考文獻對照，我們發現Bi2Te3薄膜在室溫到100K的區間裡表現出金屬性趨勢，原因是因為Te空缺所造成的雜質帶，貢獻出傳遞的載子而造成的；接著在100K到50K的區間裡，由於低溫的關係，降低載子的傳輸而使得電阻也逐漸上升，所以呈現出半導體的特性；最後在低於50K的區間則是變成了絕緣體的性質。由此可知，Te空缺的多寡除了會影響到Bi2Te3薄膜的載子濃度之外，更會進一步的去影響其物理特性的表現，因此控制Te缺陷是該系統中重要的研究目標。

In the research, the topological insulator Bi2Te3 thin film grown on sapphire(0001) by molecular beam epitaxy (MBE) in different growth conditions have been studied by RHEED, AFM, XRD and R-T measurement. The structure of Bi2Te3 thin films have the crystal orientation and flat surface morphology when the growth condition is 330℃ substrate temperature and flux ratio of Te/Bi is about 10 to 15. In electrical measurement, the R-T behavior of Bi2Te3 thin films is various in different temperature range. According to references, the results present that the electronic properties of Bi2Te3 thin films is metallic between room temperature to 100 K, which is attributed to carrier transport from the impurity band contributed the Te vacancies in Bi2Te3 thin films. In the temperature range from 100K to 50K, the carrier movement gradually is reduced due to low temperature, which result in increasing resistance. The electronic properties of Bi2Te3 thin films is semiconductor. Finally, the characteristics of Bi2Te3 thin films convert to the nature of insulator in the lower temperature range(<50 K). According to above results, the amount of Te vacancies modulate the carrier concentration in the Bi2Te3 thin film, it also change other physical characteristics of Bi2Te3 thin film. Therefore, the control of Te defect is an important research in Bi2Te3 topological insulator.

[1] J. Krumrain, G. Mussler, S. Borisova, L. Plucinski, C.M. Schneider,
D. Gru ̈tzmacher, Journal of Crystal Growth 324, 115-118 (2011)
[2] J.O. Jenkins, J.A. Rayne, R.W. Ure Jr., Phys. Rev. B 5, 3171(1972)
[3] T. Nagao, J.T. Sadowski, M. Saito, S. Yaginuma, Y. Fujikawa,
T. Kogure, T. Ohno, Y. Hasegawa, S. Hasegawa, T. Sakurai,
Phys. Rev. Lett. 93, 105501(2004)
[4] Guang Wang, ADVANCED MATERIALS 23, 2929(2011)
[5] H. B. Zhang, EPL 95, 56002(2011)
[6] J.C.A. Huang, Ph.D. Thesis, Univ. of Illinois
[7] B. Heinrich, J.A.C. Bland, Ultrathin Magnetic Structure I,
Springer-Verlag, New York(1994)
[8] 鄭文源，鈷超薄膜在銥(111)表面上的磁性研究：成長與熱退火
效應，東海大學物理系碩士論文
[9] E. Bauer, Appl. Surf. Sci 11/12, 479(1982)
[10] B. Dodson, Phys. Rev. B 36, 6288(1987)
[11] W. Wulfhekel, F. Zavaliche, R. Hertel, Phys. Rev. B 68,
144416(2003)
[12] P.J. Berlowitz, J.W. He, D.W. Googman, Surf. Sci. 231, 315(1990)
[13] H.J. Elmers, J. Hauschild, Surf. Sic. 320, 134(1994)
[14] Xiao-Liang Qi, Shou-Cheng Zhang, Physics Today, January(2010)
[15] A. Mzerd, D. Sayah, G. Brun, JOURNAL OF MATERIALS
SCIENCE LETTER 14, 194-197(1995)
[16] M.A. Herman, H. Sitter, Molecular Beam Epitaxy, Berlin
Springer(1989)
[17] 賴柜宏，白金錳薄膜合金之交換耦合效應：多層膜成長白金錳
合金及退火處理研究，成功大學物理系碩士論文(2003)
[18] 蘇書玄，鉬(001)階梯表面對鐵薄膜(001)成長與磁異向性之研
究，成功大學物理系碩士論文(2006)
[19] 邱詩航，[Si 20Å/Mn XÅ]30結構與磁、電特性研究，
成功大學物理系碩士論文(2005)
[20] 羅仁華，後退火處理對鎵、鈷共摻雜氧化鋅磁電性之研究，
成功大學物理系碩士論文(2010)
[21] 工業材料雜誌，181期，104-105(2002)
[22] Shuang Jia, Phys. Rev. B 84, 235206(2011)