resumo
Tuning the band-gap of graphene is a current need for real device applications. Copper (Cu) as a substrate plays a crucial role in graphene deposition. Here we report the fabrication of in-situ nitrogen (N) doped graphene via chemical vapor deposition (CVD) technique and the effect of Cu substrate thickness on the growth mechanism. The ratio of intensities of G and D peaks was used to evaluate the defect concentration based on local activation model associated with the distortion of the crystal lattice due to incorporation of nitrogen atoms into graphene lattice. The results suggest that Cu substrate of 20 mu m in thickness exhibits higher defect density (1.86x10(12) cm(-2)) as compared to both 10 and 25 mu m thick substrates (1.23x10(12) cm(-2) and 3.09x10(11) cm(-2), respectively). Furthermore, High Resolution -X-ray Photoelectron Spectroscopy (HR-XPS) precisely affirms similar to 0.4 at% of nitrogen intercalations in graphene. Our results show that the substitutional type of nitrogen doping dominates over the pyridinic configuration. In addition, X-ray diffraction (XRD) shows all the XRD peaks associated with carbon. However, the peak at similar to 24 degrees is suppressed by the substrate peaks (Cu). These results suggest that nitrogen atoms can be efficiently incorporated into the graphene using thinner copper substrates, rather than the standard 25 mu m ones. This is important for tailoring the properties by graphene required for microelectronic applications.
palavras-chave
CHEMICAL-VAPOR-DEPOSITION; EPITAXIAL GRAPHENE; CARBON NANOTUBES; GRAPHITE; FILMS; SURFACES; DIAMOND
categoria
Physics
autores
Sharma, DK; Fateixa, S; Hortiguela, MJ; Vidyasagar, R; Otero-Irurueta, G; Nogueira, HIS; Singh, MK; Kholkin, A
nossos autores
Andrei Kholkin
Investigador Jubilado
Dhananjay K. Sharma
Bolseiro de pós-Doutoramento
Helena Isabel Seguro Nogueira
Professor Auxiliar com Agregação
Reddithota Vidyasagar
Bolseiro de pós-Doutoramento
Sara Fateixa
Bolseiro de pós-DoutoramentoGrupos
G1 - Materiais Porosos e Nanossistemas
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
agradecimentos
DKS acknowledges Svaagata Erasmus Mundus for financial support for a PhD fellowship. S. Fateixa and R. Vidyasagar thank Fundacao para a Ciencia e Tecnologia (FCT) for the grants SFRH/BPD/93547/2013. and SFRH/BPD/104887/2014, respectively. AK is grateful to the Russian Foundation for Basic Research (grant No 16-29-14050-ofr-m) and Government of the Russian Federation (Act 211, Agreement 02.A03.21.0006) for the financial support. MJH acknowledges UID/EMS/00481/2013 project. G O-I thanks FCT for his investigator grant (IF/01054/2015). The work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by National Funds through the FCT/MEC and, when appropriate, co-funded by FEDER under the PT2020 Partnership Agreement.