Electronic and photocatalytic properties of two-dimensional boron phosphide/SiC van der Waals heterostructure with direct type-II band alignment: a first principles study.

Thi-Nga Do,Bin Amin,M Idrees,Le T Hoa,Huynh V Phuc,Nguyen V Hieu,Nguyen N Hieu,Chuong V Nguyen

doi:10.1039/d0ra05579d

Abstract

Designing van der Waals (vdW) heterostructures of two-dimensional materials is an efficient way to realize amazing properties as well as opening opportunities for applications in solar energy conversion and nanoelectronic and optoelectronic devices. In this work, we investigate the electronic, optical, and photocatalytic properties of a boron phosphide–SiC (BP–SiC) vdW heterostructure using first-principles calculations. The relaxed configuration is obtained from the binding energies, inter-layer distance, and thermal stability. We show that the BP–SiC vdW heterostructure has a direct band gap with type-II band alignment, which separates the free electrons and holes at the interface. Furthermore, the calculated absorption spectra demonstrate that the optical properties of the BP–SiC heterostructure are enhanced compared with those of the constituent monolayers. The intensity of optical absorption can reach up to about 105 cm−1. The band edges of the BP–SiC heterostructure are located at energetically favourable positions, indicating that the BP–SiC heterostructure is able to split water under working conditions of pH = 0–3. Our theoretical results provide not only a fascinating insight into the essential properties of the BP–SiC vdW heterostructure, but also helpful information for the experimental design of new vdW heterostructures.

Highlights

Dong et al.[50] constructed a lateral van der Waals (vdW) heterostructure between onedimensional (1D) zigzag boron phosphide nanoribbons and silicon carbide nanoribbons with edges terminated by hydrogen atoms
One can nd that the band edges of the boron phosphide–SiC (BP–SiC) heterostructure are located at energetically favourable positions, representing the ability of the boron phosphide (BP)–SiC heterostructure to split water under working conditions of pH 1⁄4 0–3
In the BP–SiC vdW heterostructure the VBM and CBM are from different monolayers, potentially separate the free electrons and holes

Summary

Introduction

The honeycomb structures of BP and other group III–V binary compounds have been proposed theoretically and gained extensive attention due to their exceptional electronic properties.[17,18] Practically, multilayer BP lms have been produced from the precursor of silicon carbide under chemical vapor deposition (CVD).[19] BP possesses a planar Young’s modulus and Poisson’s ratio of 135.6 N mÀ1 and 0.27, respectively, illustrating that its mechanical stability is similar to that of MoS2 and it is denser than monolayer graphene and BN It exhibits a remarkable primary direct energy band gap of 0.91 eV,[17] making it a propitious 2D material for distinctive nanoelectronics. They have the capability to signi cantly absorb light in the visible region and can split water at pH 1⁄4 0, which makes them an important candidate for applications in the elds of photovoltaics and photocatalytic devices

Computational details

Results and discussion

Conclusion