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Abstract Reliable and controllable growth of two-dimensional (2D) hexagonal boron nitride (h-BN) is essential for its wide range of applications. Substrate engineering is one of the critical factors that influence the growth of the epitaxial h-BN films. Here, we report the growth of monolayer h-BN on Ni (111) substrates incorporated with oxygen atoms via molecular beam epitaxy. It was found that the increase of incorporated oxygen concentration in the Ni substrate through a pretreatment process prior to the h-BN growth step would have an adverse effect on the morphology and growth rate of 2D h-BN. Under the same growth condition, h-BN monolayer coverage decreases exponentially as the amount of oxygen incorporated into Ni (111) increases. Density functional theory calculations and climbing image nudged elastic band (CI-NEB) method reveal that the substitutional oxygen atoms can increase the diffusion energy barrier of B and N atoms on Ni (111) thereby inhibiting the growth of h-BN films. As-grown large-area h-BN monolayer films and fabricated Al/h-BN/Ni (MIM) nanodevices were comprehensively characterized to evaluate the structural, optical and electrical properties of high-quality monolayers. Direct tunneling mechanism and high breakdown strength of ∼11.2 MV cm−1are demonstrated for the h-BN monolayers grown on oxygen-incorporated Ni (111) substrates, indicating that these films have high quality. This study provides a unique example that heterogeneous catalysis principles can be applied to the epitaxy of 2D crystals in solid state field. Similar strategies can be used to grow other 2D crystalline materials, and are expected to facilitate the development of next generation devices based on 2D crystals.
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This content will become publicly available on June 24, 2026
Ammonothermal Growth of Rhombohedral Boron Nitride
Boron nitride (BN) has numerous advantageous physical and electrical properties for mechanical and (opto‐)electronic applications, yet growing large single crystals is challenging. The ammonothermal method has demonstrated its suitability for large single‐crystal gallium nitride growth and is investigated for its ability to grow BN. The temperature‐dependent solubility of BN in sodium‐containing supercritical ammonia is previously demonstrated. Herein, the application of a temperature gradient across a baffled autoclave toward the continuous dissolution and crystallization of BN is examined. BN deposits on all wetted surfaces in the lower‐temperature zone, predominantly on the autoclave walls as polycrystalline sheets and to a lesser degree on suspended seeds of cubic BN as oriented, micrometer‐sized, repeated trapezoidal platelet units. Analysis of the grown BN crystals by Raman, X‐ray diffraction, and transmission electron microscopy suggests the growth of sp2‐hybridized BN, predominantly the rhombohedral crystal structure on nitrided NiCr alloy surfaces and rhombohedral and hexagonal crystal structures on the cubic BN seed crystal surfaces. The interfacial relationships between the cBN and the sp2‐hybridized BN phases are examined, where favorable attachment sites are discovered between the dissimilar lattices, further supporting the observed crystal growth.
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- Award ID(s):
- 1832824
- PAR ID:
- 10608911
- Publisher / Repository:
- Wiley Online Library
- Date Published:
- Journal Name:
- physica status solidi (b)
- ISSN:
- 0370-1972
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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