Synthesis of atomically thin hexagonal boron nitride films on nickel foils by molecular beam epitaxy

Hexagonal boron nitride (h-BN) is a layered 2D material with properties that make it promising as a dielectric in various applications. In particular, its integration into heterostructures with other 2D materials (e.g. graphene) has recently attracted intense interest due to the unique properties and functionalities exhibited by such hybrid systems. Hence, achieving the well-controlled and scalable synthesis of atomically thin h-BN films is important for future electronic and optoelectronic applications. However, so far the synthesis has mostly relied on transfer of micrometer-size h-BN flakes to supporting substrates.

 

Figure 1: (Top) Atomic force micrograph of a h-BN film grown on a Ni foil. Wrinkles in the h-BN film are easily observed across the entire scanned area. The average thickness of the film is ~ 0.9 nm (about three atomic layers of h-BN). (Bottom) Scanning electron micrograph (field of view = 9 μm) of a h-BN island. In this case the growth was halted prior to the formation of a closed film. The island has a “star”-shape, with multiple elongated lobes extending from a central nucleation site.

In this work, we demonstrate the feasibility of employing molecular beam epitaxy (MBE) as a method to prepare continuous h-BN films on polycrystalline Ni foils. Besides its continuity over a large area, the MBE-grown h-BN possesses high structural quality. Atomically thin films could be synthesized, which is an important achievement towards the integration of this material into complex heterostructures, in combination with atomic layers of other 2D materials. We also benefit from the high level of growth control in MBE to gain knowledge about the formation of h-BN on the substrate surface. The use of short growth times allowed us to get important insight into the nucleation and growth behavior of h-BN before forming a closed film.

1 Autor S. Nakhaie , J. M. Wofford , T. Schumann , U. Jahn , M. Ramsteiner , M. Hanke , J. M. J. Lopes , H. Riechert
Titel

Synthesis of atomically thin hexagonal boron nitride films on nickel foils by molecular beam epitaxy

Source Appl. Phys. Lett. , 106 , 213108 ( 2015 )
DOI : 10.1063/1.4921921 | Download: PDF | 2696 Cite : Bibtex RIS
S. Nakhaie, J. M. Wofford, T. Schumann, U. Jahn, M. Ramsteiner, M. Hanke, J. M. J. Lopes, and H. Riechert