The Studies Of The Surface And Interface Based On MoS₂（0001）

Abstract-. Since the establishment of Institute of Super Microstructure and Ultrafast Processes in Advanced Materials at Central south university in2011, the first STARPES system in our country has been set up. In this thesis, atomic structure and electronic properties of MoS2(0001) and interfacial electronic properties of CuPc/MoS2(0001) ave been studied with some interface surface analysis methods such as low energy electron diffraction (LEED) optics, atomic force microscope (AFM) and photoelectron spectroscopy (PES) besed on our system. The research contents are as follows:1. The STARPES system is set up for growing organic and inorganic thin films and taking the spin-time-momentum-resolved photoelectron spectroscopy tests. The system contains Analysis chamber, Organic vapor deposition chamber, MBE chamber, Multi-function chamber and so on. And then, the femtosecond laser will be introduced for time-resolved tests.2. Using mechanical cleavage we get the clean surface of MoS2(0001). The lattice structure and the brillouin zone high symmetry line (Г-K and Г-M) direction is determined by LEED. The relationship between the photoelectron emergent angle and the brillouin zone boundary is obtained by calculation.Then, the band structure along the M-F-K high symmetry line is tested by ARPES. At last, we discuss the features of MoS2(0001) band structure.3. The CuPc/MoS2(0001) heterostructure is obtained by vacuum evaporation method.The LEED patterns indicate that three equivalent well-ordered two-dimensional square lattice are formed in CuPc monolayer thin films along three surface crystalline axes of MoS2(0001) substrate, respectively. The AFM measurements show that the growth of CuPc on MoS2(0001) occurs in a Stranski-Krastanov mode. The CuPc molecule can be flat-laying on MoS2(0001) at low coverage (-0.3nm), but formed strip-like crystals along the surface crystal axes of MoS2(0001) at high coverage (>2.4nm). The CuPc molecule shows obvious anisotropy, indicating that the molecular plane is not parallel to the MoS2surface. The PES measurements show there is no charge transfer processes at the interface, indicating weak Van der Waals interactions between CuPc and MoS2(0001).