Combinatorial CuNi alloy thin film catalysts for layer number regulation in CVD grown graphene
Date of Award
Master of Science
Materials Science and Engineering
Philip D. Rack
Dustin A. Gilbert, Claudia Rawn
In this work, synthesis of combinatorial library of CuxNi1-x (copper nickel) alloy thin films via co-sputtering from Cu (copper) and Ni (nickel) targets as catalysts for chemical vapor deposition (CVD) growth of graphene is reported. The gradient 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 CuxNi1-x alloy thin films were used to grow graphene in a CH4-Ar-H2 (methane-argon-hydrogen) ambient in thermal CVD tube furnace. The underlying rationale is to adjust the CuxNi1-x alloy carbon solubility at a fixed temperature (~1000 oC) to control the graphene layer number as the solubility limit of carbon in Cu is approximately 75 +/- 0.5 ppm and C in Ni is 1.3 at.%.
The energy dispersive x-ray spectroscopy (EDS) analysis revealed that a continuous gradient of CuxNi1-x (25.29%68.95%, bilayer growth dominates from 47.56%=3) growth occurs for x<47.56%. Thus, we have overviewed the Raman analysis of the CVD grown graphene layers.
Finally, we show large area bi-layer graphene can be grown via the thin film catalyst with optimized catalyst composition.
Khanna, Sumeer, "Combinatorial CuNi alloy thin film catalysts for layer number regulation in CVD grown graphene. " Master's Thesis, University of Tennessee, 2022.