Semimetal behavior of bilayer stanene

TL;DR

This study investigates the electronic properties of fluorinated bilayer stanene, revealing its semimetal behavior and the effects of strain, with implications for its use in electronic applications.

Contribution

First-principles analysis of fluorinated bilayer stanene's electronic properties considering strain, spin-orbit, and van der Waals interactions, showing its semimetal nature and trivial insulating behavior.

Findings

Bilayer fluorinated stanene exhibits semimetal characteristics.

Tensile strain can induce a band gap, turning it into a trivial insulator.

Bilayer fluorinated stanene is not suitable as a topological insulator.

Abstract

Stanene is a two-dimensional (2D) buckled honeycomb structure which has been studied recently owing to its promising electronic properties for potential electronic and spintronic applications in nanodevices. In this article, we present a first-principles study of electronic properties of fluorinated bilayer stanene. The effect of tensile strain, intrinsic spin-orbit, and van der Waals interactions are considered within the framework of density functional theory. The electronic band structure shows a very small overlap between valence and conduction bands at the {\Gamma} point which is a characteristic of semimetal in fluorinated bilayer stanene. A relatively high value of tensile strain is needed to open an energy band gap in the electronic band structure and the parity analysis reveals that the strained nanostructure is a trivial insulator. According to our results, despite the monolayer fluorinated stanene, the bilayer one is not an appropriate candidate for topological insulator.