The Preparation Of Graphene-Metal Composite And Property Research

Graphene, a monolayer of carbon atoms packed into a hexagoanal honeycomb two-dimensional (2D) structure, has some excellent physical and chemical properties, such as high carrier mobility, thermal transport and mechanical properties. It turns out to be a gapless semiconductor with unique electronic properties resulting from the fact that charge carriers in graphene demonstrate charge-conjugation symmetry between electrons and holes and possess an internal degree of freedom similar to "chirality" for ultrarelativistic elementary particles. Furthermore, by modifying graphene, it may present better properties. Therefore, a systematic study of functionalization of graphene is desirable, which is the subject of this thesis. With regard to its high surface/volume ration, which provide perfect substrate for different metal atoms to modulate its band structure feasibly and conveniently.In recent years, the chemical vapor deposition (CVD) bottom-up synthesis methods have been well developed to produce scalable area and high-quality graphene, however comparing the properties of CVD-produced graphene to those exfoliated graphene, the latter continues to exhibit better quality so far. For this reason, we make every effort to synthesis single layer graphene with high quality for our later graphene-based research work. We decorated the pure graphene with metal nanoparticles (Au?Ti?Cu?Ni?Al) by using electron beam evaporator, thus we obtained the graphene-metal nano-composite materials. In addition, we deposited NbN films of different thickness on the graphene samples and studied the influence of graphene on the NbN superconducting properties. The abundant physical information about hall effect and magnetoresistance of the composite materials makes our investigation very meaningful, Which is deserved to be further studied. The main works are listed as below:1. Graphene samples were successfully obtained via CVD method and the influence factors of preparing graphene, including the flow ration between carbon source and carrier gas, growth time, temperature and the pre-treatment of copper substrate was studied in detail.2. High quality graphene samples were characterized by the Optical Microscope, Raman, SEM, and were prepared for further research. The pure graphene films were decorated with different metal nanoparticles by using the methods of electron beam evaporator?magnetron sputtering and sintering under high temperature, besides further characterization of Raman and SEM were did systematically. The influence of the metal nanoparticles on the electrical properties of graphene were investigated in detail through the comparison of characterization.3. In view of the magnetism of nickel and remarkable change of Raman characterization in Ni/graphene samples, its electrical and physical properties such as hall effect and manetoresistance were further researched in detail.4. With the consideration of the excellent superconducting properties of NbN films, we deposited NbN films on the graphene surface and further characterized the thickness of NbN films and its superconductivity properties.