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arXiv · 2210.09991

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

Changmeng Huan·Pu Wang·Bingtao Liu·Binghan He·Yongqing Cai·Qingqing Ke
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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.

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Changmeng Huan, Pu Wang, Bingtao Liu, Binghan He, Yongqing Cai, Qingqing Ke. 2022-10-17. Versatile van der Waals Heterostructures of Gamma-GeSe with h-BN/Graphene/MoS2. https://doi.org/10.1039/d2tc02105f

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