The Molecular Beam Epitaxy Growth Of Topological Material ZrTe₅and Cd₃As₂

Topological materials such as topological insulator and topological semimetal have become a central issue in the study of condensed state physics in recent years, their exotic characteristics are expected to be applied in quantum calculation and spin electronic devices, which will bring revolutionary breakthrough to information technology.The growth and surface state measurement are fundamental to the study and application of topological materials, and the films obtained are more convenient for the production of electronic devices. most of the existing growth methods for single crystal sample are based on the chemical vapor deposition. When comparing to these methods, the molecular beam epitaxy(MBE) growth has the advantages such as easy to control the orientation of the growth and the thickness of the single crystals. However,no single-crystal film of ZrTes and Cd3As2has been obtained by MBE growth. Aiming at this, this paper have investigated the MBE growth of two typical topological including topological insulator ZrTes and topological semimetal Cd3As2, the main contents and results are:1. We explore the preparing methods for atomically flat SrTiO3(STO) substrate the used in the MBE growth, atomic force microscope (AFM) is used to measure the results;2. The MBE growth results of topological insulator ZrTes under different conditions are measured, then the most appropriatetemperature and flux ratio are determined, the influence induced by different substrate are also discussed. The measure results obtained from AFM, X-ray diffraction, Raman spectra show the successful growth of high quality ZrTes film;3. Multiple substrates are used in the MBE growth of topological semimetal Cd3As2with two-step methods, results obtained from AFM, XRD and X-ray photoelectron spectroscopy(XPS) show that InP is the most appropriate substrate for Cd3As2, the preparing method for substrate and most suitable growth condition are also presented;4. The mechanism of the influence that growing temperature and flux ratio bring to MBE growth is discussed.