Adsorption of Mo and O at S-vacancy on ReS2 surface of ReS2/MoTe2 vdW heterointerface

TL;DR

This study uses density functional theory to analyze how sulfur vacancies and atom adsorption at the ReS2/MoTe2 heterointerface affect electronic properties and switching behavior in ultra-thin 2D heterostructures for nanoelectronic applications.

Contribution

It provides a detailed theoretical analysis of defect-induced states and atom adsorption effects on the electronic properties of ReS2/MoTe2 heterostructures, which was not previously explored.

Findings

Adsorption of Mo and O at S-vacancy modulates the energy gap.

Defect-induced states significantly influence electronic properties.

Surface adsorption energies indicate potential for switching applications.

Abstract

Applications like high density information storage, neuromorphic computing, nanophotonics, etc. require ultra-thin electronic devices which can be controlled with applied electric field. Of late, atomically thin two-dimensional (2D) materials and van der Waals (vdW) heterointerface of those have emerged as suitable candidates for such ultra-low power nanoelectric devices. In this work, employing density functional theory (DFT), the monolayer ReS2 / monolayer MoTe2 vdW heterostructure with Sulphur vacancy is studied to examine various ground state electronic properties. Changes in effective band gap owing to defect-induced states and modulation of the energy gap value with Molybdenum (Mo) and Oxygen (O) adsorption at the defect site are examined. Since two-dimensional (2D) material based nanoscaled devices exhibit promising switching between non-conducting and conducting states, determining the role of defect-induced states and the adsorption of atoms/molecules on surfaces is crucial. Here, a detailed theoretical study to determine surface properties and relative energetic stability of the vdW heterostructures is carried out. The charge re-distribution between the constituent layers is also analyzed by obtaining Electron Difference Density (EDD) for different heterointerfaces. Nonetheless, the efficacy of switching between non-conducting and conducting states is assessed based on adsorption energy of adatoms binding at the defect site.