The dynamics of copper intercalated molybdenum ditelluride

TL;DR

This paper develops a reactive force field for molybdenum ditelluride and copper interactions, enabling large-scale simulations of intercalation, adhesion, and ion mobility relevant to nanoelectronics and energy applications.

Contribution

The authors created and validated a ReaxFF force field for MoTe2 and Cu, capturing energetics, charges, and mechanical properties, facilitating atomistic simulations beyond first principles.

Findings

Good agreement with DFT on MoTe2 adhesion to Cu(111)

Cu ion mobility increases with electric field and concentration

Significant drift velocity enhancement at 0.4 V/A electric field

Abstract

Layered transition metal dichalcogenides are emerging as key materials in nanoelectronics and energy applications. Predictive models to understand their growth, thermomechanical properties and interactions with metals are needed in order to accelerate their incorporation into commercial products. Interatomic potentials enable large-scale atomistic simulations at the device level, beyond the range of applications of first principle methods. We present a ReaxFF reactive force field to describe molybdenum ditelluride and its interactions with copper. We optimized the force field parameters to describe the properties of layered MoTe2 in various phases, the intercalation of Cu atoms and clusters within its van der Waals gap, including a proper description of energetics, charges and mechanical properties. The training set consists of an extensive set of first principle calculations computed from density functional theory. We use the force field to study the adhesion of a single layer MoTe2 on a Cu(111) surface and the results are in good agreement with density functional theory, even though such structures were not part of the training set. We characterized the mobility of the Cu ions intercalated into MoTe2 under the presence of an external electric fields via molecular dynamics simulations. The results show a significant increase in drift velocity for electric fields of approximately 0.4 V/A and that mobility increases with Cu ion concentration.