First-principles study of the electronic structures and optical and photocatalytic performances of van der Waals heterostructures of SiS, P and SiC monolayers.

Qaisar Alam,Nguyen T T Binh,M Idrees,S Muhammad,Bin Amin,Nguyen V Hieu,C Nguyen

doi:10.1039/d0ra10808a

Abstract

Designing van der Waals (vdW) heterostructures of two-dimensional materials is an efficient way to realize amazing properties as well as open up opportunities for applications in solar energy conversion, nanoelectronic and optoelectronic devices. The electronic structures and optical and photocatalytic properties of SiS, P and SiC van der Waals (vdW) heterostructures are investigated by (hybrid) first-principles calculations. Both binding energy and thermal stability spectra calculations confirm the stability of these heterostructures. Similar to the corresponding parent monolayers, SiS–P (SiS–SiC) vdW heterostructures are found to be indirect type-II bandgap semiconductors. Furthermore, absorption spectra are calculated to understand the optical behavior of these systems, where the lowest energy transitions lie in the visible region. The valence and conduction band edges straddle the standard redox potentials of SiS, P and SiC vdW heterostructures, making them promising candidates for water splitting in acidic solution.

Highlights

A er the discovery of graphene,[1] two dimensional (2D) materials, such as hexagonal boron nitride (h-BN),[2] transition metal dichalcogenides (TMDCs),[3] silicon carbide (SiC),[4] MXenes,[5] phosphorene[6] and BSe,[7] have shown superior performances over their bulk counterparts because of their large surface areas and high concentrations of open-transport channels.[8,9] Among these 2D materials, much attention has been paid to the silicon sul de (SiS) monolayer, which is a group IV–VI material.[10]
We have systematically investigated the electronic structures, band edge alignments and optical properties of the combination between SiC(P) and SiS to form SiS–SiC (SiS–P) van der Waals (vdW) heterostructures using density functional theory
The geometric relaxations are performed by the Perdew–Burke–Ernzerhof (PBE) functional,[43] until the forces converged to 10À4 eV AÀ1 and the energy to 10À5 eV, and the HSE06 (Heyd–Scuseria–Ernzerhof) functional[44] is used for electronic structure calculations

Summary

Introduction

A er the discovery of graphene,[1] two dimensional (2D) materials, such as hexagonal boron nitride (h-BN),[2] transition metal dichalcogenides (TMDCs),[3] silicon carbide (SiC),[4] MXenes,[5] phosphorene[6] and BSe,[7] have shown superior performances over their bulk counterparts because of their large surface areas and high concentrations of open-transport channels.[8,9] Among these 2D materials, much attention has been paid to the silicon sul de (SiS) monolayer, which is a group IV–VI material.[10]. Jing et al.[15] predicted that the SiS monolayer exhibits a large negative Poisson’s ratio, tunable electronic properties under strain and anisotropic carrier mobility. This material is a potential candidate for optoelectronic applications.

Methods

Results

Conclusion