Exploring electronic, optical, and phononic properties of MgX (X=C, N, and O) monolayers using first principle calculations

TL;DR

This study uses first principles calculations to analyze the electronic, optical, and thermal properties of MgX monolayers (X=C, N, O), revealing their stability and potential applications in nanoelectronics and thermal management.

Contribution

It provides a comprehensive first-principles analysis of MgX monolayers, highlighting their stability and distinct electronic and optical properties, especially the semiconducting nature of MgO.

Findings

MgO monolayer is a stable semiconductor with active near-UV optical response.

MgC and MgN monolayers are metallic with IR optical activity.

All three monolayers exhibit excellent dynamic stability.

Abstract

The electronic, the thermal, and the optical properties of hexagonal MgX monolayers (where X=C, N, and O) are investigated via first principles studies. Ab-initio molecular dynamic, AIMD, simulations using NVT ensembles are performed to check the thermodynamic stability of the monolayers. We find that an MgO monolayer has semiconductor properties with a good thermodynamic stability, while the MgC and the MgN monolayers have metallic characters. The calculated phonon band structures of all the three considered monolayers shows no imaginary nonphysical frequencies, thus indicating that they all have excellent dynamic stability. The MgO monolayer has a larger heat capacity then the MgC and the MgN monolayers. The metallic monolayers demonstrate optical response in the IR as a consequence of the metal properties, whereas the semiconducting MgO monolayer demonstrates an active optical response in the near-UV region. The optical response in the near-UV is beneficial for nanoelectronics and photoelectric applications. A semiconducting monolayer is a great choice for thermal management applications since its thermal properties are more attractive than those of the metallic monolayer in terms of heat capacity, which is related to the change in the internal energy of the system.