Electronic Structure and Room Temperature of 2D Dilute Magnetic Semiconductors in Bilayer MoS2-Doped Mn

Sintayehu Mekonnen Hailemariam

doi:10.1155/2020/9635917

Abstract

The electronic structure and magnetic properties of manganese- (Mn-) doped bilayer (BL) molybdenum disulfide (MoS2) are studied using the density function theory (DFT) plus on-site Hubbard potential correction (U). The results show that the substitution of Mn at the Mo sites of BL MoS2 is energetically favorable under sulfur- (S-) rich regime than Mo. The magnetic interaction between the two manganese (Mn) atoms in BL MoS2 is always ferromagnetic (FM) irrespective of the spatial distance between them, but the strength of ferromagnetic interaction decays with atomic distance. It is also found that two dopants in different layers of BL MoS2 communicate ferromagnetically. In addition to this, the detail investigation of BL MoS2 and its counterpart of monolayer indicates that interlayer interaction in BL MoS2 affects the magnetic interaction in Mn-doped BL MoS2. The calculated Curie temperature is 324, 418, and 381 K for impurity concentration of 4%, 6.25%, and 11.11%, respectively, which is greater than room temperature, and the good dilute limit of dopant concentration is 0–6.25%. Based on the finding, it is proposed that Mn-doped BL MoS2 are promising candidates for two-dimensional (2D) dilute magnetic semiconductor (DMS) for high-temperature spintronics applications.

Highlights

It is known that graphene is the most well-known member in the family of 2D materials
On contrary to zero band gap graphene, other group of 2D materials so called transition metal dichalcogenides (TMDS) with chemical formula MX2, where M stands for transition metals like molibidium (Mo), tungeston (W), and so on and X stands for chalcogen atoms like selfur (S), selenium (Se), and telenium (Te), and so on are more recently discovered [2]. e experimental study reveals that the weak van der Waals forces between each 2D monolayer of which they are formed allow thin multilayers to be exfoliated from their bulk form [3]
In MoS2 materials, the electronic structure depends on the number of layers which mean that there is a gradual transition from an indirect band gap (1.3 eV) in the bulk material to a direct gap in the ML material with band gap 1.9 eV which reveals that the interlayer van der Waals (VdW) interaction may affect the electronic structure [6]

Summary

Introduction

It is known that graphene is the most well-known member in the family of 2D materials. E experimental study reveals that the weak van der Waals forces between each 2D monolayer of which they are formed allow thin multilayers to be exfoliated from their bulk form [3] Among those families, monolayer MoS2 and few layer MoS2 have attracted interest due to their potential application [2, 4]; for instance, the monolayer (ML) MoS2 has emerged as a semiconductor with a large intrinsic direct band gap of approximately 1.8 eV [3], which makes it suitable for nanoelectronic and optoelectronic applications [5]. Electronic structure and magnetic interaction in Mn-doped bilayer (BL) MoS2 has not yet been studied in detail. Based on mean field theory together with empirical correction, the Curie temperature (Tc) is estimated

Computational Details

Result and Discussion

Findings

Mn N NN

Conclusion