Spin-polarised DFT modeling of electronic, magnetic, thermal and optical properties of silicene doped with transition metals

TL;DR

This study uses spin-dependent DFT to explore how transition metal doping affects silicene's electronic, magnetic, thermal, and optical properties, revealing strong interactions, high magnetic moments, and potential for advanced nanodevices.

Contribution

It provides a systematic analysis of TM-doped silicene's properties, highlighting the effects of doping on structure, magnetism, and optical transitions, which was not comprehensively studied before.

Findings

TM atoms reduce silicene buckling due to strong interaction.

Parallel bands cause visible and UV optical transitions.

High Curie temperature ferromagnetic states are favored.

Abstract

The geometric, electronic, magnetic, thermal, and optical properties of transition metal (TM) doped silicene are systematically explored using spin-dependent density functional computation. We find that the TM atoms decrease the buckling degree of the silicene structure caused by the interaction between the dopant TM atoms and the Si atoms in the silicene layer plane which is quite strong. In some TM-silicenes, parallel bands and the corresponding van Hove singularities are observed in the electronic band structure without and with spin-polarization. These parallel bands are the origin of most of the transitions in the visible and the UV regions. A high Seebeck coefficient is found in some TM-silicene without spin-polarization. In the presence of emergent spin-polarization, a reduction or a magnification of the Seebeck coefficient is seen due to a spin-dependent phase transition. We find that the preferred state is a ferromagnetic state with a very high Curie temperature. We observe a strong interaction and large orbital hybridization between the TM atoms and the silicene. As a result, a high magnetic moment emerges in TM-silicene. Our results are potentially beneficial for thermospin, and optoelectronic nanodevices.