Influência do tratamento de hidrogênio no crescimento de grafeno a baixa pressão

• Ano de defesa: 2013
• Autor(a) principal: Welyson Tiano dos Santos Ramos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Física; Estrutura cristalina; Deposição quimica de vapor; Cobre; Espectroscopia de Raman; Grafeno
• Link de acesso: http://hdl.handle.net/1843/BUBD-9ESEWR

In this work we are interested in studying the influence of hydrogen (due to the annealing step of the copper) in the growth process of graphene on copper sheets, using the technique of chemical vapor deposition (LPCVD). For this purpose, we propose two different ways of exposing the copper to gases used in the process: encapsulating the copper between two quartz plates; leaving a copper surface directly exposed to the gases. We are interested in understanding the effects of heat treatment (using H2 during the annealing step) on the surface of the copper. For this, we use the technique of scanning electron microscopy (SEM) and atomic force microscopy (AFM). A correlation was observed between the surface roughness of the copper (after treatment) and H2 concentration used in the treatment, and the treatment procedure encapsulated provides a surface more suitable for the growth. We also observed that the use of high concentrations of hydrogen during annealing of copper causes tears in graphene films. Furthermore, we want to establish an ideal condition for the growth of graphene and get films of monolayer graphene of high quality. We intend to facilitate the process of transfer these films to SiO2/Si. The graphene films obtained were characterized by different techniques, including: SEM, optical microscopy and Raman spectroscopy.