Effect of Surface Functional Groups on the Electronic Behavior and Optical Spectra of Mn2N Based MXenes

Abstract

The extensive applications of MXenes, a novel type of layered materials known for their favorable characteristics, have sparked significant interest. This research focuses on investigating the influence of surface functionalization on the behavior of Mn₂NT_x (T_x=O₂, F₂) MXenes monolayers using the "Density functional theory (DFT) based full-potential linearized augmented-plane-wave (FP-LAPW)" method. We elucidate the differences in the physical properties of Mn₂NT_x through the influence of F and O surface functional groups. We found that O-termination results in half-metallic behavior, whereas the F-termination evolves metallic characteristics within these MXene systems. Similarly, surface termination has effectively influenced their optical absorption efficiency. For instance, Mn₂NO₂ and Mn₂NF₂ effectively absorb UV light ~50.15×10⁴ cm^-1 and 37.71×10⁴ cm^-1, respectively. Additionally, they demonstrated prominent refraction and reflection characteristics, which are comprehensively discussed in the present work. Our predictions offer valuable perspectives into the optical and electronic characteristics of Mn₂NT_x-based MXenes, presenting the promising potential for implementing them in diverse optoelectronic devices.

Keywords: Absorption coefficients; Electronic structures; MXenes; Mn2NTx; O- and F- Surface Termination.