Preparation And Properties Of Topological Insulator Sb₂Te₃ System

The three-dimensional topological insulator is a new quantum state of matter with special surface state, has become a frontier research fields of physics and material science in recent years. Topological insulator material is an insulator, the surface is protected by time reversal symmetry of the gapless metal state. The surface state is determined by the topological properties of electron states, by the time reversal symmetry protection, not easy to be affected by defects and impurities in the system. Therefore, can be ordered through electronic channels in topological insulators, no collision between each other, there is no energy dissipation. It is expected to solve the bottleneck of semiconductor devices face. Therefore, whether has the unique application value in basic research or in a quantum computer, thermoelectric effect and the spin electronic devices.In this study, we take Bi, Se, Sb, Te of the substance as the source material, the use of molecular beam epitaxy on sapphire substrate epitaxial growth of a topological insulator material with high quality, and carry on research by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy and other instruments on the thin film material the growth of the surface morphology and properties. The results of the dissertation are as follows:By molecular beam epitaxy (MBE) method, the topological insulator Sb2Te3 grown on sapphire (Al2O3) substrates, successfully established a topological insulator crystal structure. By using scanning electron microscopy, on the sapphire substrate, the growth process of Sb2Te3 and the surface structure of the sample has been studied and analyzed; We study the growth process of Sb2Te3 thin film on a substrate Al2O3, got high quality Sb2Te3, and through the verification of our conclusion that the X ray diffraction analysis of the image.