Epitaxial Growth and Structural Characterization of BiTeSe Alloy

• Main Authors: Zhi-XiangDeng, 鄧至翔
• Other Authors: Jung-Chun Huang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/05777473471578888678

碩士 === 國立成功大學 === 物理學系 === 103 === This study systemically investigates the structural and electric transport properties of Bi2Te3-xSex topological insulator alloys by varying the growth temperature of Bi2Te3-xSex and fixed the Bi:Te:Se flux ratio using molecular beam epitaxy (MBE). The surfaces of the alloys exhibit terrace-like quintuple layers and their sizes vary with the Te/Se ratio and the size of the characteristic triangular terraces of the Bi2Te3-xSex films decreases monotonically with the Se content increases. The lattice constant decreases linearly with the degree of Se doping concentration. All the Bi2Te3-xSex films have good structures and surfaces. The surface carrier concentration of the Bi2Te3-xSex film exhibits the largest surface concentration and the film resistivity reaches a maximum when Te:Se = 2:1. Optimal atomic and electronic structures as well as the electrical transport properties of Bi2Te3-xSex thin film alloys can be obtained by fine-tuned growth conditions, suggesting that Bi2Te3-xSex thin film alloy with this ratio is an excellent template for doping and investigating the properties of topological insulators.