Journal article
Bottom-Up-Etching Mediated Synthesis of Large-Scale Pure Monolayer Graphene on Cyclic-Polishing-Annealed Cu(111)
Beijing National Laboratory for Molecular Sciences1
Department of Physics, Technical University of Denmark2
Nanomaterials and Devices, Department of Physics, Technical University of Denmark3
Department of Photonics Engineering, Technical University of Denmark4
Ultrafast Infrared and Terahertz Science, Department of Photonics Engineering, Technical University of Denmark5
Center for Nanostructured Graphene, Centers, Technical University of Denmark6
Peking University7
Synthesis of large-scale single-crystalline graphene monolayers without multilayers involves the fabrication of proper single-crystalline substrates and the ubiquitous formation of multilayered graphene islands during chemical vapor deposition. Here, a method of cyclic electrochemical polishing combined with thermal annealing, which allows the conversion of commercial polycrystalline Cu foils to single-crystal Cu(111) with an almost 100% yield, is presented.
A global “bottom-up-etching” method that is capable of fabricating large-area pure single-crystalline graphene monolayers without multilayers through selectively etching bottom multilayered graphene underneath large area as-grown graphene monolayer on Cu(111) surface is demonstrated. Terahertz time-domain spectroscopy (THz-TDS) measurement of the pure monolayer graphene film shows a high average sheet conductivity of 2.8 mS and mean carrier mobility of 6903 cm2 V−1 s−1 over a large area.
Density functional theory (DFT) calculations show that the selective etching is induced by the much easier diffusion of hydrogen atoms than hydrocarbon radicals across the edges of the top graphene layer, and the simulated selective etching processes based on phase field modeling are well consistent with experimental observations.
This work provides new ways toward the production of single-crystal Cu(111) and the synthesis of pure monolayer graphene with high electronic quality.
Language: | English |
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Year: | 2022 |
Pages: | e2108608 |
ISSN: | 15214095 and 09359648 |
Types: | Journal article |
DOI: | 10.1002/adma.202108608 |
ORCIDs: | 0000-0001-5521-2316 , Zhou, Binbin , Bøggild, Peter and Jepsen, Peter Uhd |