Monolayer graphene growth on Ni(111) by low temperature chemical vapor deposition

Abstract Here, we report a novel method for low-temperature synthesis of monolayer graphene at 450 °C on a polycrystalline bimetal Ni-Au catalyst. In this study, low-temperature chemical vapor deposition synthesis of graphene was performed at 450 °C on codeposited Ni-Au which shows successful monolayer graphene formation without an extra annealing process. The experimental results suggest that electron beam codeposition of bimetal catalyst is the key procedure that enables the elimination of the pre-growth high-temperature annealing of the catalyst prior to graphene synthesis, an indispensable process, used in previous reports. The formation was further improved by plasma-assisted growth in which the inductively coupled plasma ionizes the carbon precursors that interact with codeposited Ni-Au catalyst of 50 nm in thickness at 450 °C. These combined growth conditions drastically increase the graphene’s sheet uniformity and area connectivity from 11.6% to 99%. These fabrication parameters enable the graphene formation that shifts from a bulk diffusion-based growth model towards a surface based reaction. The technique reported here opens the opportunity for the low-temperature growth of graphene for potential use in future CMOS applications.

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Growth Phase Diagram of Graphene Grown Through Chemical Vapor Deposition on Copper

NANO ◽

10.1142/s1793292020501374 ◽

2020 ◽

Vol 15 (10) ◽

pp. 2050137 ◽

Cited By ~ 1

Author(s):

Qinke Wu ◽

Sangjun Jeon ◽

Young Jae Song

Keyword(s):

Electron Microscopy ◽

Phase Diagram ◽

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Vapor ◽

Copper Surface ◽

Monolayer Graphene ◽

Multilayer Graphene ◽

Graphene Growth ◽

Graphene Layers

The phase diagram for graphene growth was obtained to understand the physics of the growth mechanism and control the layer number or coverage of graphene deposited on copper via low-pressure chemical vapor deposition (LPCVD). Management of the number of graphene layers and vacancies is essential for producing defect-free monolayer graphene and engineering multilayered functionalized graphene. In this work, the effects of the CH4 and H2 flow rates were investigated to establish the phase diagram for graphene growth. Using this phase diagram, we selectively obtained fully covered and partially grown monolayer graphene, graphene islands through Volmer–Weber growth, and multilayer graphene through Stranski–Krastanov-like growth. The layer numbers and coverage were determined using optical microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy and Raman spectroscopy. The growth modes were determined by the competition between catalytic growth with CH4 and catalytic etching with H2 on the copper surface during CVD growth. Intriguingly, this phase diagram showed that multilayer graphene flakes can be grown via LPCVD even with low CH4 and H2 flows.

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