Electronic Properties of Transferable Atomically Thin MoSe<sub>2</sub>/h-BN Heterostructures Grown on Rh(111).

Chen, Ming-Wei; Kim, HoKwon; Bernard, Carlo; Pizzochero, Michele; Zaldı Var, Javier; Pascual, Jose Ignacio; Ugeda, Miguel M; Yazyev, Oleg V et al. · ACS Nano · 2018

basic_science · Level V

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Abstract

Vertically stacked two-dimensional (2D) heterostructures composed of 2D semiconductors have attracted great attention. Most of these include hexagonal boron nitride (h-BN) as either a substrate, an encapsulant, or a tunnel barrier. However, reliable synthesis of large-area and epitaxial 2D heterostructures incorporating BN remains challenging. Here, we demonstrate the epitaxial growth of nominal monolayer (ML) MoSe<sub>2</sub> on h-BN/Rh(111) by molecular beam epitaxy, where the MoSe<sub>2</sub>/h-BN layer system can be transferred from the growth substrate onto SiO<sub>2</sub>. The valence band structure of ML MoSe<sub>2</sub>/h-BN/Rh(111) revealed by photoemission electron momentum microscopy ( kPEEM) shows that the valence band maximum located at the K point is 1.33 eV below the Fermi level ( E<sub>F</sub>), whereas the energy difference between K and Γ points is determined to be 0.23 eV, demonstrating that the electronic properties, such as the direct band gap and the effective mass of ML MoSe<sub>2</sub>, are well preserved in MoSe<sub>2</sub>/h-BN heterostructures.