title: Direct Growth of MoS₂/h-BN Heterostructures via a Sulfide-Resistant Alloy.
abstract: Improved properties arise in transition metal dichalcogenide (TMDC) materials when they are stacked onto insulating hexagonal boron nitride (h-BN). Therefore, the scalable fabrication of TMDCs/h-BN heterostructures by direct chemical vapor deposition (CVD) growth is highly desirable. Unfortunately, to achieve this experimentally is challenging. Ideal substrates for h-BN growth, such as Ni, become sulfides during the synthesis process. This leads to the decomposition of the pregrown h-BN film, and thus no TMDCs/h-BN heterostructure forms. Here, we report a thoroughly direct CVD approach to obtain TMDCs/h-BN vertical heterostructures without any intermediate transfer steps. This is attributed to the use of a nickel-based alloy with excellent sulfide-resistant properties and a high catalytic activity for h-BN growth. The strategy enables the direct growth of single-crystal MoS2 grains of up to 200 μm(2) on h-BN, which is approximately 1 order of magnitude larger than that in previous reports. The direct band gap of our grown single-layer MoS2 on h-BN is 1.85 eV, which is quite close to that for free-standing exfoliated equivalents. This strategy is not limited to MoS2-based heterostructures and so allows the fabrication of a variety of TMDCs/h-BN heterostructures, suggesting the technique has promise for nanoelectronics and optoelectronic applications.
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Fu
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Yangyong
authors.initials: Y
authors.lastname: Sun
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Nian
authors.initials: N
authors.lastname: Wu
authors.affiliation: IFW Dresden , P.O. Box 270116, 01069 Dresden, Germany.
authors.forename: Rafael G
authors.initials: RG
authors.lastname: Mendes
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Linfeng
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: IFW Dresden , P.O. Box 270116, 01069 Dresden, Germany.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Rümmeli
authors.affiliation: IFW Dresden , P.O. Box 270116, 01069 Dresden, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Rellinghaus
authors.affiliation: IFW Dresden , P.O. Box 270116, 01069 Dresden, Germany.
authors.forename: Darius
authors.initials: D
authors.lastname: Pohl
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhuang
authors.affiliation: College of Chemistry and Molecular Science, Wuhan University , Wuhan 430072, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Fu
keywords: MoS2/h-BN heterostructures; direct CVD growth; optical properties; sulfide-resistant alloy