CVD-graphene growth on different polycrystalline transition metals

The chemical vapor deposition (CVD) graphene growth on two polycrystalline transition metals (Ni and Cu) was investigated in detail using Raman spectroscopy and optical microscopy as a way to synthesize graphene of the highest quality (i.e. uniform growth of monolayer graphene), which is considered...

Full description

Bibliographic Details
Authors: Lavín López, María del Prado; Sánchez Silva, María Luz; Valverde, Jose Luis; Romero Izquierdo, Amaya
Format: Article
Publication date:2017
Country:España
Institution:Universidad de Castilla-La Mancha
Repository:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/29676
Online Access:http://hdl.handle.net/10578/29676
Access Level:Open access
Keyword:CVD-graphene
Carbon solubility
Carbon diffusion
Thickness
Monolayer
Copper
Polycrystalline metal
CVD-grafeno
Solubilidad del carbono
Difusión de carbono
Espesor
Monocapa
Cobre
Níquel
Metal policristalino
Description
Summary:The chemical vapor deposition (CVD) graphene growth on two polycrystalline transition metals (Ni and Cu) was investigated in detail using Raman spectroscopy and optical microscopy as a way to synthesize graphene of the highest quality (i.e. uniform growth of monolayer graphene), which is considered a key issue for electronic devices. Key CVD process parameters (reaction temperature, CH4/H2flow rate ratio, total flow of gases (CH4+H2), reaction time) were optimized for both metals in order to obtain the highest graphene uniformity and quality. The conclusions previously reported in literature about the performance of low and high carbon solubility metals in the synthesis of graphene and their associated reaction mechanisms, i.e. surface depositionand precipitation on cooling, respectively, was not corroborated by the results obtained in this work. Under the optimal reaction conditions, a large percentage of monolayer graphene was obtained over the Ni foil since the carbon saturation was not complete, allowing carbon atoms to be stored in the bulk metal, which could diffuse forming high quality monolayer graphene at the surface. However, under the optimal reaction conditions, the formation of a non-uniform mixture of few layers and multilayer graphene on the Cu foil was related to the presence of an excess of active carbon atoms on the Cu surface