First Principles Study on the Electronic Structure and Interface Stability of Hybrid Silicene/Fluorosilicene Nanoribbons.

Q G Jiang,Y P Wu,J F Zhang,Z M Ao

doi:10.1038/srep15734

Abstract

The interface stability of hybrid silicene/fluorosilicene nanoribbons (SFNRs) has been investigated by using density functional theory calculations, where fluorosilicene is the fully fluorinated silicene. It is found that the diffusion of F atoms at the zigzag and armchair interfaces of SFNRs is endothermic, and the corresponding minimum energy barriers are respectively 1.66 and 1.56 eV, which are remarkably higher than the minimum diffusion energy barrier of one F atom and two F atoms on pristine silicene 1.00 and 1.29 eV, respectively. Therefore, the thermal stability of SFNRs can be significantly enhanced by increasing the F diffusion barriers through silicene/fluorosilicene interface engineering. In addition, the electronic and magnetic properties of SFNRs are also investigated. It is found that the armchair SFNRs are nonmagnetic semiconductors, and the band gap of armchair SFNRs presents oscillatory behavior when the width of silicene part changing. For the zigzag SFNRs, the antiferromagnetic semiconducting state is the most stable one. This work provides fundamental insights for the applications of SFNRs in electronic devices.

Highlights

For practical applications, the two dimensional materials are usually cut into one dimensional nanoribbons
The configurations with the F atom adsorbed at sites 0–3 are initial state (IS), final state 1 (FS1), final state 2 (FS2) and final state 3 (FS3) during the transition state search, respectively
We have studied the stability of silicene/fluorosilicene nanoribbons (SFNRs) with both zigzag and armchair interfaces by calculating the diffusion barriers of F atoms using density functional theory (DFT) method

Summary

Introduction

The two dimensional materials are usually cut into one dimensional nanoribbons. Be fabricated by selectively fluorinating silicene by using a low-damage plasma treatment or exposing to atomic F formed by decomposition of XeF2 with masking techniques, or by removing F atoms from fluorosilicene by electron beam, as proposed for the graphene system[24,25,26]. Both of experimental and theoretical studies on SFNRs are absent. The thermal stability of SFNRs is determined by calculating the diffusion barrier of F atoms at the silicene/fluorosilicene interface. All the possible diffusion pathways at the interface are analysed to search the minimum diffusion barrier, and to provide guidance for designing viable silicene electronic devices that possess high thermal stability and excellent electronic and magnetic properties at the operating conditions

Methods

Results

Conclusion