Combinatorial Cu-Ni Alloy Thin-Film Catalysts for Layer Number Control in Chemical Vapor-Deposited Graphene

Nanomaterials

卷:12

Philip D. Rack¹  Sumeer R. Khanna¹  Michael G. Stanford²  Ivan V. Vlassiouk³ 

[1] Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA;

[2] General Graphene Corporation, Knoxville, TN 37932, USA;

[3] Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA;

关键词: thin film;    combinatorial sputtering;    alloys;    catalyst;    graphene;    2D materials;   

DOI  :  10.3390/nano12091553

来源: DOAJ

【 摘 要 】

We synthesized a combinatorial library of Cu_xNi_1−x alloy thin films via co-sputtering from Cu and Ni targets to catalyze graphene chemical vapor deposition. The alloy morphology, composition, and microstructure were characterized via scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and X-ray diffraction (XRD), respectively. Subsequently, the Cu_xNi_1−x alloy thin films were used to grow graphene in a CH₄-Ar-H₂ ambient at atmospheric pressure. The underlying rationale is to adjust the Cu_xNi_1−x composition to control the graphene. Energy dispersive x-ray spectroscopy (EDS) analysis revealed that a continuous gradient of Cu_xNi_1−x (25 at. % < x < 83 at.%) was initially achieved across the 100 mm diameter substrate (~0.9%/mm composition gradient). The XRD spectra confirmed a solid solution was realized and the face-centered cubic lattice parameter varied from ~3.52 to 3.58 $\dot{\mathrm{A}}$, consistent with the measured composition gradient, assuming Vegard’s law. Optical microscopy and Raman analysis of the graphene layers suggest single layer growth occurs with x > 69 at.%, bilayer growth dominates from 48 at.% < x < 69 at.%, and multilayer (≥3) growth occurs for x < 48 at.%, where x is the Cu concentration. Finally, a large area of bi-layer graphene was grown via a Cu_xNi_1−x catalyst with optimized catalyst composition and growth temperature.

【 授权许可】

Unknown