Electronic structures and enhanced optical properties of blue phosphorene/transition metal dichalcogenides van der Waals heterostructures

Qiong Peng,Baisheng Sa,Bo Wu,Zhenyu Wang,Zhimei Sun

doi:10.1038/srep31994

Abstract

As a fast emerging topic, van der Waals (vdW) heterostructures have been proposed to modify two-dimensional layered materials with desired properties, thus greatly extending the applications of these materials. In this work, the stacking characteristics, electronic structures, band edge alignments, charge density distributions and optical properties of blue phosphorene/transition metal dichalcogenides (BlueP/TMDs) vdW heterostructures were systematically studied based on vdW corrected density functional theory. Interestingly, the valence band maximum and conduction band minimum are located in different parts of BlueP/MoSe2, BlueP/WS2 and BlueP/WSe2 heterostructures. The MoSe2, WS2 or WSe2 layer can be used as the electron donor and the BlueP layer can be used as the electron acceptor. We further found that the optical properties under visible-light irradiation of BlueP/TMDs vdW heterostructures are significantly improved. In particular, the predicted upper limit energy conversion efficiencies of BlueP/MoS2 and BlueP/MoSe2 heterostructures reach as large as 1.16% and 0.98%, respectively, suggesting their potential applications in efficient thin-film solar cells and optoelectronic devices.

Highlights

For getting self-consistent results, we evaluated the accurate band gap values by the hybrid-density functional theory (DFT) method with 8% Hartree-Fock exchange energy based on the optB86b-van der Waals (vdW) approach for all the monolayers and heterostructures, which exactly reproduces the experimental gap of monolayer MoS2
We have systematically studied the stacking configurations induced electronic structures, band edge alignments, charge density distributions and optical properties of blue phosphorene (BlueP)/TMDs vdW heterostructures based on vdW corrected density functional theory
The negative formation energies as well as the good lattice match protect the thermodynamic stability of the BlueP/TMDs vdW heterostructures

Summary

Introduction

The MoS2/hBN heterostructure could serve as a prototypical example for band structure engineering of 2D crystals with atomic layer precision[10]. It is worth noting that the lattice parameter of BlueP matches with many TMDs (for example, MoS2, MoSe2, WS2 and WSe2) perfectly. In this regard, investigating the electronic and optical properties of BlueP/TMDs vdW heterostructures is anticipated and of great interest and importance. The structural, electronic and optical properties of BlueP/TMDs (TMDs =MoS2, MoSe2, WS2 and WSe2) vdW heterostructures were systematically studied using first-principles calculations based on the density functional theory (DFT). The band-decomposed charge density and optical spectra were evaluated to understand the nature of the bonding mechanism, charge transfer as well as the visible-light absorption ability of the BlueP/TMDs vdW heterostructures

Methods

Results

Discussion

Conclusion