First-principles Investigations of Magnetic Semiconductors: An example of Transition Metal Decorated Two-dimensional SnS Monolayer

Abstract

The absence of magnetic moments in pristine two-dimensional (2D) semiconducting materials has attracted many research interests. Transition-metal (TM) decoration has been found to be an effective strategy to introduce magnetic moments in non-magnetic 2D semiconductors. However, the stability of TM atoms modified 2D semiconductors has not been well explored. Here, taking 2D Tin (II) sulfide (SnS) monolayer as a prototype, we explored the stability of magnetic semiconductors through this method. In our studies, all possible configurations of TM decoration have been considered, namely, adsorption on the intact surface, S vacancy, and Sn vacancy. Based on the energy gain and electronic analysis, our results revealed that most of the TM atoms will form a cluster, and only several TM atoms can be effectively doped into the SnS monolayer. Furthermore, the band calculations showed that only Mn substitution will give rise to a magnetic semiconductor. Thus, the reported results here provide some hidden information for further realization of the magnetic semiconductors and serve as a paradigm to prepare 2D magnetic semiconductors.

Boosting the Curie Temperature of Two-Dimensional Semiconducting CrI3 Monolayer through van der Waals Heterostructures

“…These materials have a unique potential for new physical phenomena, because magnetism occurs spontaneously without the need to introduce magnetic dopants, as done in conventional magnetic semiconductors. − As a result, a perfect crystalline order is preserved. The above discoveries have motivated a great deal of interest in related 2D ferromagnetic materials (e.g., Fe 3 GeTe 2 , CrOCl, and CrWI 6 ). − Unlike 2D FM metals, which show a very high T C even up to room temperature (e.g., VSe 2 and MnSe 2 ), the T C of CrI 3 FM semiconductor is only ∼45 K, which hinders its potential for practical applications. Therefore, many works have been devoted to improving T C of 2D ferromagnetic materials. − …”

Defect pairing in Fe-doped SnS van der Waals crystals: a photoemission and scanning tunneling microscopy study

“…Instead, our findings support a recent DFT work by ref. 8 where the authors predict that Fe defects could also lower their formation energies by structural relaxation in the vicinity of intrinsic vacancy defects. Indeed, in the coupled (V Sn , Fe int ) defect suggested in our work, Fe accommodates a site with a nearest neighbor distance of 2.45 Å, much smaller than in an unrelaxed substitutional Fe Sn cite with an Fe–S distance of 2.66 Å.…”

“…For Sn-chalcogenides, we are aware of two recent density functional theory (DFT) studies addressing the bonding of dilute 3d transition metal guest atoms to SnSe and SnS layers for potential spintronic and magneto-optic applications. 7,8…”

Prediction of two-dimensional monochalcogenides: MoS and WS

“…We find that the puckered structure has a different geometry compared to the other 2D monochalcogenides as reported in Ref. [24][25][26][27]31 In what follows, we present the methodology used in this study, in the next section. We discuss our results in the following section and finally we summarize and conclude in the last section.…”

“…On the other hand, it has been observed in the literature that some of the 2D monochalcogenides (namely, CSe, GeSe, SnS etc) possess the puckered phosphorene-like structures. [24][25][26][27][28][29][30][31] Therefore, in this work, we explore both the (buckled and puckered) structures, in order to search for the lowest energy phase of MoS and WS monolayer materials. For the puckered structure, we probe various different positions of Mo(W) with respect to the S atoms 32 and the energetically lowest configuration is reported in this study where Mo(W) occupies the adjacent sites and S occupies the edge sites.…”