Interfacial electronic properties and tunable band offset in graphyne/MoSe2 heterostructure with high carrier mobility

Abstract

Graphyne-based two-dimensional heterostructures have displayed excellent potential in nanoelectronic devices. Herein, a novel vertical graphyne/MoSe₂ van der Waals (vdW) heterostructure is constructed and its electronic and interfacial properties are systematically studied. The calculated results reveal that the graphyne/MoSe₂ vdW heterostructure has semiconductor characteristics with a direct bandgap and an intrinsic type-I band alignment, where the conduction band minimum and valence band maximum are both contributed by the graphyne monolayer. In addition, high carrier mobility (10⁴ cm² V⁻¹ s⁻¹) and strong optical absorption (10⁵ cm⁻¹) are observed in the graphyne/MoSe₂ vdW heterostructure. More importantly, the type-I band alignment in the graphyne/MoSe₂ vdW heterostructure is robust against an external electric field, and the band offset of the graphyne/MoSe₂ vdW heterostructure can be effectively tuned by the external electric field, which is crucial to the luminous efficiency of light-emitting devices. Our results provide new strategies for designing graphyne-based heterostructures with broad application prospects in light-emitting devices.