A type-II PtS2/MoTe2 van der Waals heterostructure with adjustable electronic and optical properties

Abstract

The geometrical, electronic, and optical properties of the PtS2/MoTe2 heterostructure are systematically investigated based on the density functional theory (DFT) calculations. The indirect bandgap (0.93 eV) PtS2/MoTe2 heterostructure shows high dynamical and mechanical stability at room temperature. Type-II band alignment of the system facilitates the separation of photogenerated electrons and holes at the interface. Biaxial strain and external electric field (Efield) can not only induce the band alignment of the PtS2/MoTe2 heterostructure transition from type-II to type-I, but also can realize semiconductor–metal transition. The PtS2/MoTe2 heterostructure can occur redshift with a peak appearing near infrared region and its power conversion efficiency (PCE) reaches 13.60%. These properties are beneficial for application in infrared detector and solar cells. In addition, biaxial strain enhances the light adsorption intensity of the PtS2/MoTe2 heterostructure and tensile strain expands the light adsorption range. The adsorption intensity increases with the Efield increasing, implying the Efield can effectively modulate the optical properties. Our results indicate that the PtS2/MoTe2 heterostructure has a bright prospect in the application of solar cell, infrared detector, optoelectronic and nanoelectronic devices, as well as provide a useful theoretical direction for the fabrication of PtS2/MoTe2 heterostructure.

Keywords

• vdWHs
• Band alignment
• PtS2
• MoTe2
• First-principles calculations
• 2D materials