Tuning electronic and optical properties of bismuth monolayers by molecular adsorption

TL;DR

This study uses first-principles calculations to explore how molecular adsorption modifies the electronic and optical properties of bismuth monolayers, revealing topological insulating behavior and significant dielectric anisotropy.

Contribution

It demonstrates that functionalizing bismuthene with small ligands induces topological insulating phases and alters dielectric properties, providing insights for material engineering.

Findings

All functionalized structures exhibit topological insulator behavior.

Adsorption induces a quasi-planar structure in bismuthene.

Dielectric properties show large anisotropy with two main in-plane absorption peaks.

Abstract

We perform first-principles calculations of electronic and dielectric properties of bismuthene functionalized with small ligands using first-principle calculations. We show that all functionalized structures have topological insulating (TI) behavior with a sizeable gap by calculating the Z$_2$ topological invariant. Furthermore the adsorption of all groups induce a quasi-planar structure to the initially pristine bismuthene structure. Finally we show that the dielectric properties show a large anisotropy with two main in plane absorption peaks.