Atomic Layer Epitaxy of h-BN(0001) Multilayers on Co(0001) and Molecular Beam Epitaxy Growth of Graphene on h-BN(0001)/Co(0001)
Autor: | Kimberly G. Reid, Jeffry A. Kelber, Opeyemi Olanipekun, Ashutosh Rath, Paul M. Voyles, M. Sky Driver, John Beatty |
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Rok vydání: | 2016 |
Předmět: |
Nanotechnology
02 engineering and technology Substrate (electronics) 010402 general chemistry 01 natural sciences law.invention law Monolayer Electrochemistry Atomic layer epitaxy General Materials Science Spectroscopy Low-energy electron diffraction Graphene business.industry Chemistry Heterojunction Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Band bending Optoelectronics 0210 nano-technology business Molecular beam epitaxy |
Zdroj: | Langmuir. 32:2601-2607 |
ISSN: | 1520-5827 0743-7463 |
Popis: | The direct growth of hexagonal boron nitride (h-BN) by industrially scalable methods is of broad interest for spintronic and nanoelectronic device applications. Such applications often require atomically precise control of film thickness and azimuthal registry between layers and substrate. We report the formation, by atomic layer epitaxy (ALE), of multilayer h-BN(0001) films (up to 7 monolayers) on Co(0001). The ALE process employs BCl3/NH3 cycles at 600 K substrate temperature. X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) data show that this process yields an increase in h-BN average film thickness linearly proportional to the number of BCl3/NH3 cycles, with BN layers in azimuthal registry with each other and with the Co(0001) substrate. LEED diffraction spot profile data indicate an average BN domain size of at least 1900 Å. Optical microscopy data indicate the presence of some domains as large as ∼20 μm. Transmission electron microscopy (TEM) and ambient exposure studies demonstrate macroscopic and microscopic continuity of the h-BN film, with the h-BN film highly conformal to the Co substrate. Photoemission data show that the h-BN(0001) film is p-type, with band bending near the Co/h-BN interface. Growth of graphene by molecular beam epitaxy (MBE) is observed on the surface of multilayer h-BN(0001) at temperatures of 800 K. LEED data indicate azimuthal graphene alignment with the h-BN and Co(0001) lattices, with domain size similar to BN. The evidence of multilayer BN and graphene azimuthal alignment with the lattice of the Co(0001) substrate demonstrates that this procedure is suitable for scalable production of heterojunctions for spintronic applications. |
Databáze: | OpenAIRE |
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