title: Large-area growth of multi-layer hexagonal boron nitride on polished cobalt foils by plasma-assisted molecular beam epitaxy.
abstract: Two-dimensional (2D) hexagonal boron nitride (h-BN), which has a similar honeycomb lattice structure to graphene, is promising as a dielectric material for a wide variety of potential applications based on 2D materials. Synthesis of high-quality, large-size and single-crystalline h-BN domains is of vital importance for fundamental research as well as practical applications. In this work, we report the growth of h-BN films on mechanically polished cobalt (Co) foils using plasma-assisted molecular beam epitaxy. Under appropriate growth conditions, the coverage of h-BN layers can be readily controlled by growth time. A large-area, multi-layer h-BN film with a thickness of 5~6 nm is confirmed by Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. In addition, the size of h-BN single domains is 20~100 μm. Dielectric property of as-grown h-BN film is evaluated by characterization of Co(foil)/h-BN/Co(contact) capacitor devices. Breakdown electric field is in the range of 3.0~3.3 MV/cm, which indicates that the epitaxial h-BN film has good insulating characteristics. In addition, the effect of substrate morphology on h-BN growth is discussed regarding different domain density, lateral size, and thickness of the h-BN films grown on unpolished and polished Co foils.
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Zhongguang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Tian
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Alireza
authors.initials: A
authors.lastname: Khanaki
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Renjing
authors.initials: R
authors.lastname: Zheng
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Suja
authors.affiliation: Quantum Structures Laboratory, Department of Electrical and Computer Engineering, University of California, Riverside, California 92521, USA.
authors.forename: Jianlin
authors.initials: J
authors.lastname: Liu