Research On Graphene Grown From Metal-catalyzed SiC

Graphene exhibits low friction in vacuum and have low sensitivity to the environment,meanwhile graphene also shows excellent electrical properties and thermal performance,lays the foundation for low friction integrate with super thermal conductive and electric conductive as next space solid lubrication.However,the major bottleneck of graphene application is still the optimization of graphene's preparation technology and the bonding strength between transferred graphene and different substrates is usually very weak.In this paper,graphene is prepared on amorphous Silicon Carbide and the catalytic metal of Cobalt,both on cemented carbide which have Cobalt as binding phase,and Silicon wafer,by vacuum annealing.The effect of different technological parameter of the amorphous Silicon Carbide content to generate graphene is studied,and reaction mechanism of the process were analyzed.Then conducted different series of Cobalt and Silicon Carbide content research,to find a process route to prepare graphene controllably.The results obtained were as following:(1)Transfer-free graphene is synthesized on cemented carbide,and with sublimation of Silicon atoms,the structure of Carbon atoms precipitation has changed,at the same time,number of layers and quality of graphene changed.The study of relationship between graphene and precipitation layer shows that,when content of Silincon atoms decreased,free metal phase may catalyse cabon atoms form graphene layer,content of silicon atoms decrease,defect of graphene less and number layers of graphene reduces first then increases.(2)The variation of metal catalyst affect the generated graphene.Compared to Cobalt deposited on silicon carbide,when the catalytic metal contace with substrate hard to form graphene under shorter annealing time.Graphene quality improves with metal layer thickness increases,advantageous to the graphene formation.Prior to silicon carbide annealed with cobalt,when cobalt pre-annealing for a large grain size,there had no significant effect of generated graphene.(3)Adjust the structure of the carbon source have a significant influence on graphene formation.When amorphous silicon carbide annealing for crystallization,the quality of graphene improves and have a tendency to form few-layer graphene.When content of silicon atoms in silicon carbide crystal decreases,number layers of graphene reduces and quality improves.When silicon carbide replaced by diamond as carbon source,graphene can formation too,but number layers of graphene more.