DFT investigation of the electronic and optical properties of hexagonal MX2/ZrXO (M = W, Mo and X = S, Se) van der Waals heterostructures for photovoltaic solar cell application

Abstract

The van der Waals heterostructure of Janus materials with a TMD monolayer was used to create a two-dimensional class of nanomaterials for photovoltaic solar cell applications. It is one of the potential methods for enhancing the performance of photovoltaic systems. Two monolayers of different 2D materials, Janus (ZrXO) and TMDs (MX₂), are stacked together to form the heterojunction. Based on density functional theory structural, electrical, and optical properties were investigated. The favorable stacking and stability of the MX₂/ZrXO (M = W, Mo and X = S, Se) van der Waals heterostructures are confirmed through binding energies, phonon dispersion and ab initio molecular dynamics calculations. Standard excitonic peaks, which correspond to the bound valence-band hole and conduction-band electron, as well as excitonic peaks involving the mid-gap charges, can be seen in the system's computed absorption spectrum. MX₂/ZrXO van der Waals heterostructures are excellent photovoltaic candidates with a maximum achived power conversion efficiency of above 22%. Furthermore, we discovered that the heterostructure materials have a high absorption efficiency which is good for the intended photovoltaic solar cell application.