Atomically thin two dimensional hexagonal boron nitride (2D h-BN) is one of the key materials in the development of new van der Waals heterostructures due to its outstanding properties including an atomically smooth surface, high thermal conductivity, high mechanical strength, chemical inertness and high electrical resistance. The development of 2D h-BN growth is still in the early stages and largely depends on rapid and accurate characterization of the grown monolayer or few layers h-BN films. This paper demonstrates a new approach to characterizing monolayer h-BN films directly on metal substrates by grazing-incidence infrared reflection absorption spectroscopy (IRRAS). Using h-BN films grown by atmospheric-pressure chemical vapor deposition on Cu and Ni substrates, two new sub-bands are found for the A2u out-of-plane stretching mode. It is shown, using both experimental and computational methods, that the lower-energy sub-band is related to 2D h-BN coupled with substrate, while the higher energy sub-band is related to decoupled (or free-standing) 2D h-BN. It is further shown that this newly-observed fine structure in the A2u mode can be used to assess, quickly and easily, the homogeneity of the h-BN-metal interface and the effects of metal surface contamination on adhesion of the layer.
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http://dx.doi.org/10.1039/c4nr05557h | DOI Listing |
Molecules
November 2024
Institute of Materials Science, Kaunas University of Technology, K. Baršausko St. 59, LT-51423 Kaunas, Lithuania.
In the present research, hexagonal boron nitride (h-BN) films were deposited by reactive high-power impulse magnetron sputtering (HiPIMS) of the pure boron target. Nitrogen was used as both a sputtering gas and a reactive gas. It was shown that, using only nitrogen gas, hexagonal-boron-phase thin films were synthesized successfully.
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October 2024
Institute of High Pressure Physics, Polish Academy of Sciences, 01-142 Warsaw, Poland.
Hexagonal boron nitride (h-BN) is recognized as a 2D wide bandgap material with unique properties, such as effective photoluminescence and diverse lattice parameters. Nitride alloys containing h-BN have the potential to revolutionize the electronics and optoelectronics industries. The energy band structures of three boron-containing nitride alloys-BAlN, BGaN, and BInN-were calculated using standard density functional theory (DFT) with the hybrid Heyd-Scuseria-Ernzerhof (HSE) function to correct lattice parameters and energy gaps.
View Article and Find Full Text PDFSmall
December 2024
CNRS, Georgia Tech - CNRS IRL 2958, 2 rue Marconi, Metz, 57070, France.
Hexagonal boron nitride (h-BN) bubbles are of significant interest to micro-scale hydrogen storage thanks to their ability to confine hydrogen gas molecules. Previous reports of h-BN bubble creation from grown h-BN films require electron beams under vacuum, making integrating with other experimental setups for hydrogen production impractical. Therefore, in this study, the formation of h-BN bubbles is demonstrated in a 20 nm h-BN film grown on a sapphire substrate with a 213 nm UV laser beam.
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September 2024
Institute of Materials and Systems for Sustainability (IMaSS) & Department of Materials Chemistry, Nagoya University, Nagoya, 464-8601, Japan.
Phys Chem Chem Phys
July 2024
Key Laboratory of MEMS of Ministry of Education, School of Integrated Circuits, Southeast University, Nanjing, 210096, China.
During the process of synthesizing h-BN on Cu foil chemical vapor deposition (CVD), low-pressure CVD (LPCVD) typically synthesizes monolayer h-BN films, whereas atmospheric pressure CVD (APCVD) yields few-layer h-BN films. Herein, a growth mechanism for monolayer and few-layer h-BN on Cu foil is proposed using first-principles calculations: Cu(111) passivated h-BN hinders the diffusion of B and N atoms at the subsurface of Cu(111), preventing sufficient transportation of B and N atoms to the existing h-BN layer, thereby leading to the formation of monolayer h-BN in LPCVD. For APCVD, the edges of h-BN are passivated by H, which decreases the barrier energy for the diffusion of B and N atoms on the Cu(111) subsurface, and B and N atoms can easily migrate from the subsurface of Cu(111) to its surface, resulting in the nucleation of h-BN between the existing h-BN and Cu(111), and leading to the formation of few-layer h-BN films.
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