Electronic structure and optical spectra of MSi₂N₄ (M = Mo, Ta, V) materials with single-atom decoration: a first-principles study

MoSi2N4 has outstanding potential for applications in electronics, spintronics, and semiconducting fabrication. This attractive scenario can be attributed to its remarkable electronic properties. In this study, we investigate the electronic structure and optical spectra of the MSi2N4 (M = Mo, Ta, and V) materials with single atom (H, N, and O) decoration using first-principles calculations. Pristine MoSi2N4 and VSi2N4 are semiconductors, and TaSi2N4 shows the half-metal properties. Decorating MoSi2N4 with single hydrogen and nitrogen atoms induces a magnetic moment. Single oxygen decorated TaSi2N4 does not change its intrinsic electronic properties, which is suitable for spintronic applications. On top of that, the semiconductor VSi2N4 can be turned into a half-metal via single hydrogen atom decoration. The absorption spectra demonstrate an enhancement in optical absorption for VSi2N4 after the decoration with a single nitrogen atom. Single atom decoration is one of the effective methods of tailoring the electronic properties of the two-dimensional MoSi2N4 family. Our findings can accelerate the development of the advanced electronic devices.