Controlled synthesis of uniform multilayer hexagonal boron nitride films on Fe2B alloy.

Zhiyuan Shi,Ren Jiang,Guangyuan Lu,Peng Yang,Chao Zhang,Tianru Wu,Xiaoming Xie,Weijun Yin

doi:10.1039/c9ra00595a

Abstract

Two-dimensional (2D) hexagonal boron nitride (h-BN) is highly appreciated for its excellent insulating performance and absence of dangling bonds, which could be employed to maintain the intrinsic properties of 2D materials. However, controllable synthesis of large scale multilayer h-BN is still very challenging. Here, we demonstrate chemical vapor deposition (CVD) growth of multilayer h-BN by using iron boride (Fe2B) alloy and nitrogen (N2) as precursors. Different from the self-limited growth mechanism of monolayer h-BN on catalytic metal surfaces, with sufficient B source in the bulk, Fe2B alloy promotes the controllable isothermal segregation of multilayer h-BN by reacting with active N atoms on the surface of the substrate. Microscopic and spectroscopic characterizations prove the high uniformity and crystalline quality of h-BN with a highly orientated layered lattice structure. The achievement of large scale multilayer h-BN in this work would facilitate its applications in 2D electronics and optoelectronics in the future.

Highlights

The achievement of large scale multilayer hexagonal boron nitride (h-BN) in this work would facilitate its applications in 2D electronics and optoelectronics in the future
The schematic of ambient-pressure chemical vapor deposition (CVD) setup for multilayer hBN growth was depicted in Fig. 1a
The full-width at half maximum (FWHM) of the Raman E2g band is associated with the crystallinity of h-BN.[24,25,26]

Summary

Introduction

Two-dimensional (2D) materials have attracted enormous attention for future electronic and optoelectronic device integrations.[1,2,3] Hexagonal boron nitride (h-BN), a 2D insulator with a wide band gap ($6 eV), is in general highly desired for practical device applications, such as gate dielectric layers, tunnelling barriers or encapsulations.[4,5,6,7] It is widely regarded as an ideal dielectric substrate for 2D materials because of its atomic atness and absence of dangling bonds, which could maintain the intrinsic properties of the overlying 2D materials.[3,5,6,8] single phonon emission from isolated point defect sites in h-BN has been investigated recently, which demonstrates potential in quantum photonics and quantum computation.[9,10,11]So far, many efforts have been devoted to synthesize highquality h-BN lms. In recent years, layered h-BN akes, Here, we report a new method to synthesize multilayer h-BN on Fe2B alloy with N2 as a reactant. The new synthesis method yields large scale and high quality multilayer h-BN at ambient pressure. Fe2B, an alloy supplies boron source directly, and reacts with N2 to form multilayer h-BN. The entire growth process breaks the traditional self-limited growth mechanism on catalytic metal substrates and successfully obtains multilayer h-BN on Fe2B alloy. Controllable synthesis of h-BN lm establishes a signi cant approach for further rational catalyst design for other compound 2D materials

Methods

Results

Conclusion