A DFT insight into magnetic, optoelectronic and thermoelectric properties of h-Zn1-xCuxS monolayer

[Display omitted] •Substitutional CuZn gives a stable planar structure and ferromagnetic phase.•Zn1-xCuxS-2D shows p-type conduction with a narrow band gaps.•A potential application in spintronic devices is found for low Cu concentrations.•Transparent Zn1-xCuxS-2D monolayer exhibits high thermoelectric properties.•h-Zn1-xCuxS-2D are suitable for solar cells and solar thermal energy conversion. In this study, we used the density functional theory (DFT) method to analyze the effect of Cu insertion on the structural stability, electronic, magnetic, optical and thermoelectric properties of the hexagonal ZnS monolayer (h-ZnS-2D). Our findings show that Cu replaces zinc sites by giving a stable planar structure in Ferromagnetic (FM) phase with slight decrease in the lattice parameter. A p-type semiconductor with a direct band gap that decreases with increasing Cu concentration was obtained. The half-metallic character found for low Cu concentrations let consider the h-Zn1-xCuxS-2D for potential applications in spintronic devices. The optical properties show that the h-Zn1-xCuxS-2D monolayers have high absorption and low transmittance in the UV range. The improved figure of merit of h-Zn1-xCuxS-2D due to increased electrical conductivity and decreased thermal conductivity with Cu content, makes these nanostructures a promising absorber for thin-film solar cells and suitable for solar thermal energy conversion technologies.