Versatile van der Waals Heterostructures of Gamma-GeSe with h-BN/Graphene/MoS2

Abstract

Recent discovery of a novel hexagonal phase of GeSe (Gamma-GeSe) has triggered great interests in nanoelectronics applications owing to its electrical conductivity of bulk phase even higher than graphite while its monolayer is a semiconductor. For potential applications, construction of functional two-dimensional (2D) contacts is indispensable. Herein, via first-principles calculations, we propose the design of van der Waals heterostructures (vdWHs) of Gamma-GeSe contacting respectively with graphene, 2D h-BN and MoS2, as representatives of metallic, insulator, and semiconductor partners. Our work shows that the h-BN or graphene layer donates electrons to the Gamma-GeSe layer, resulting in n doping in Gamma-GeSe, while the MoS2 layer accepts electrons from the Gamma-GeSe layer leading to p doping of the latter. The Gamma-GeSe/BN heterostructure has a type-I band alignment with large band offsets, indicating that BN can be used as an effective passivating layer to protect Gamma-GeSe from its environmental disturbance while maintaining its major electronic and optical characteristics. For Gamma-GeSe/graphene heterostructure, it is prone to have a very low-Schottky barrier down to tens of meV, easily overcome by thermal excitation, which can be tunable by strain and external electric field. The Gamma-GeSe/MoS2 vdWH forms a Z-scheme interface, which is beneficial for carriers splitting and photon utilization. Our work indicates that Gamma-GeSe can be well passivated by BN, and form intimate contact with graphene for high charge injection efficiency and with MoS2 for efficient carriers splitting for redox reactions.

References in corpus (8)

• Electric Field Effect in Atomically Thin Carbon Films
• Strong interlayer coupling in van der Waals heterostructures built from single-layer chalcogenides
• Van der Waals heterostructures for spintronics and opto-spintronics
• The Electronic Properties of Phosphorene/Graphene and Phosphorene/Hexagonal Boron Nitride Heterostructures
• Interlayer Exciton Optoelectronics in a 2D Heterostructure p-n Junction
• The Role of H2O and O2 Molecules and Phosphorus Vacancies in the Structure Instability of Phosphorene
• γ-GeSe:a new hexagonal polymorph from group IV-VI monochalcogenides
• Quasiparticle band structures, spontaneous polarization, and spin-splitting in noncentrosymmetric few-layer and bulk $\gamma$-GeSe

Cited by in corpus (1)

• Abnormal behavior of preferred formation of cationic vacancy from the interior in γ-GeSe monolayer with the stereo-chemical antibonding lone-pair state