Dispersion-Corrected Density Functional Theory Investigations of Structural and Electronic Properties of Bulk MoS2: Effect of Uniaxial Strain.

Chuong V Nguyen,Nguyen N Hieu,Duong T Nguyen

doi:10.1186/s11671-015-1099-5

Chuong V Nguyen, Nguyen N Hieu + Show 1 more

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https://doi.org/10.1186/s11671-015-1099-5

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Abstract

Strain-dependent structural and electronic properties of MoS2 materials are investigated using first principles calculations. The structural and electronic band structures of the MoS2 with relaxed unit cells are optimized and calculated by the dispersion-corrected density functional theory (DFT-D2). Calculations within the local density approximation (LDA) and GGA using PAW potentials were also performed for specific cases for the purpose of comparison. The effect of strain on the band gap and the dependence of formation energy on strain of MoS2 are also studied and discussed using the DFT-D2 method. In bulk MoS2, the orbitals shift towards the higher/lower energy area when strain is applied along the z/x direction, respectively. The energy splitting of Mo4d states is in the range from 0 to 2 eV, which is due to the reduction of the electronic band gap of MoS2.

Highlights

Molybdenum disulphide (MoS2) is an interesting material for applications in nanoelectronic applications due to its unique mechanical, electronic, and optical properties [1, 2]
We considered the where EKS-DFT is the usual self-consistent Kohn–Sham energy as obtained from the chosen DFT and Edisp is an empirical dispersion correction
By using three different methods, our calculations show that the lattice parameter a for the bulk MoS2 is 3.116, 3.172, and 3.176 Å corresponding to the local density approximation (LDA), generalized gradient approximation (GGA), and DFT-D2 methods, respectively

Summary

Introduction

Molybdenum disulphide (MoS2) is an interesting material for applications in nanoelectronic applications due to its unique mechanical, electronic, and optical properties [1, 2]. It is a typical layered inorganic material, which is similar to graphite. Due to the interlayer vdW interaction, the bulk MoS2 tends to form a bilayer which is known to be an indirect semiconductor. It has indirect energy band gap of 1.23 eV [6].

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