Functionalization of monolayer MoS2 by substitutional doping: A first-principles study

Qu, Yue; Chang, Soon-Bok; Qin, Shiqiao; Li, Jingbo

doi:10.1016/j.physleta.2013.03.034

Cited by 304 publications

(188 citation statements)

References 44 publications

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“…From a fabrication point of view, such codoping is complicated and difficult to control. However, it is predicted that ferromagnetism can be achieved by the substitution of S by nonmetal elements, such as H, B, N, and F, among which B and N induce hole doping with a magnetic moment of 1μ B [41]. In this reference it also has been demonstrated that B S is the most stable configuration.…”

mentioning

confidence: 87%

Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

2014

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We demonstrate that valley polarization can be induced and controlled in semiconducting single-layer transition-metal dichalcogenides by magnetic doping, which is important for spintronics, valleytronics, and photonics devices. As an example, we investigate Mn-doped MoS 2 by first-principles calculations. We study how the valley polarization depends on the strength of the spin orbit coupling and the exchange interaction and discuss how it can be controlled by magnetic doping. Valley polarization by magnetic doping is also expected for other honeycomb materials with strong spin orbit coupling and the absence of inversion symmetry. The fields of electronics and spintronics require an active control and manipulation of the charge and spin degrees of freedom [1]. Valleytronics, on the other hand, is very new field that relies on the property that the conduction/valence bands have two or more minima/maxima at equal energy but different momenta. For valleytronics devices it is necessary to induce valley polarization, i.e., control the number of electrons in each valley, typically by strain [2] or a magnetic field [3,4]. In general, two-dimensional materials have raised a lot of interest both for fundamental and applied reasons. Examples are semiconductor quantum wells [5], noble metal surfaces [6], graphene [7], and topological insulators [8]. Semiconducting single-layer transition metal dichalcogenides MX 2 with M = Mo, W and X = S, Se, Te and the D 3h point group have caught attention, because they display distinctively different physical properties as compared to their bulk compounds with the D 6h point group. There exists a crossover from an indirect band gap in multilayers to a direct band gap in the single-layer limit [9][10][11][12]. In the latter the conduction and valence band edges are located at the K points of the two-dimensional hexagonal Brillouin zone. These two inequivalent valleys constitute a binary index for low energy carriers, which gives rise to a valley Hall effect and valley dependent optical selection rules for interband transitions at the K points [13][14][15]. It has been demonstrated that optical pumping with circularly polarized light can achieve a dynamic valley polarization in single-layer MoS 2 [16][17][18]. However, from the application point of view an equilibrium valley polarization is desirable, which is the topic of the present paper.The interplay between spin orbit coupling and ferromagnetism in two-dimensional materials gives rise to a variety of unconventional phenomena, such as the quantum anomalous Hall effect [19][20][21][22]. In addition, it recently has been put forward that dichalcogenides doped with magnetic transitionmetal atoms form a promising platform for two-dimensional dilute magnetic semiconductors [23][24][25]. However, these studies did not take into account the spin orbit coupling, which interconnects the spin and valley physics. We propose in this paper a method to control the valley polarization by magnetic doping. Various possible Mn doping sites in single-l...

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mentioning

confidence: 87%

Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

2014

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“…Among the most interesting properties of 2D MX 2 materials is the tunability of their electronic structures. For instance, deep gap states can be induced by the presence of defects such as vacancies, lattice antisites, doping and so on [11][12][13][14] . The bandgaps are tunable with layer thickness [15][16][17][18] and stress [19][20][21] , and edge-dependent semiconducting-to-metallic transitions have been observed 22 , as well as transformations between different stacking geometries 23 , for example, 2H to 1T phase of monolayer molybdenum disulphide (MoS 2 ) 24 .…”

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confidence: 99%

Bandgap tunability at single-layer molybdenum disulphide grain boundaries

et al. 2015

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Two-dimensional transition metal dichalcogenides have emerged as a new class of semiconductor materials with novel electronic and optical properties of interest to future nanoelectronics technology. Single-layer molybdenum disulphide, which represents a prototype two-dimensional transition metal dichalcogenide, has an electronic bandgap that increases with decreasing layer thickness. Using high-resolution scanning tunnelling microscopy and spectroscopy, we measure the apparent quasiparticle energy gap to be 2.40±0.05 eV for single-layer, 2.10±0.05 eV for bilayer and 1.75±0.05 eV for trilayer molybdenum disulphide, which were directly grown on a graphite substrate by chemical vapour deposition method. More interestingly, we report an unexpected bandgap tunability (as large as 0.85 ± 0.05 eV) with distance from the grain boundary in single-layer molybdenum disulphide, which also depends on the grain misorientation angle. This work opens up new possibilities for flexible electronic and optoelectronic devices with tunable bandgaps that utilize both the control of two-dimensional layer thickness and the grain boundary engineering.

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“…), after substituting the central Mo atom in the MoS 2 monolayer, still own uncoupled d electrons, leading to ferromagnetism in the TM-MoS 2 systems [39]. The same mechanisms were observed in the single-layered MoS 2 complexes where the S atom is replaced by TMs [58,60,62], and the TM-adsorbed ZnO monolayer. Partial magnetic moments can also be allocated to the host elements, but are limited in rather small contributions to the total magnetism.…”

Section: Magnetic Interactionsmentioning

confidence: 63%

“…It is further noticed that the s-or p-type dopants can also contribute to the final ferromagnetism in ILCs. In the S substitution cases, the non-metallic light elements introduce ferrimagnetism up to 1 µ B [60]. The MMs are mainly arisen from the unpaired Mo 4d electrons due to a lack of bonding electrons from the guests.…”

Section: Magnetic Interactionsmentioning

confidence: 99%

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Introducing Magnetism into 2D Nonmagnetic Inorganic Layered Crystals: A Brief Review from First-Principles Aspects

et al. 2018

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Pioneering explorations of the two-dimensional (2D) inorganic layered crystals (ILCs) in electronics have boosted low-dimensional materials research beyond the prototypical but semi-metallic graphene. Thanks to species variety and compositional richness, ILCs are further activated as hosting matrices to reach intrinsic magnetism due to their semiconductive natures. Herein, we briefly review the latest progresses of manipulation strategies that introduce magnetism into the nonmagnetic 2D and quasi-2D ILCs from the first-principles computational perspectives. The matrices are concerned within naturally occurring species such as MoS 2 , MoSe 2 , WS 2 , BN, and synthetic monolayers such as ZnO and g-C 2 N. Greater attention is spent on nondestructive routes through magnetic dopant adsorption; defect engineering; and a combination of doping-absorbing methods. Along with structural stability and electric uniqueness from hosts, tailored magnetic properties are successfully introduced to low-dimensional ILCs. Different from the three-dimensional (3D) bulk or zero-dimensional (0D) cluster cases, origins of magnetism in the 2D space move past most conventional physical models. Besides magnetic interactions, geometric symmetry contributes a non-negligible impact on the magnetic properties of ILCs, and surprisingly leads to broken symmetry for magnetism. At the end of the review, we also propose possible combination routes to create 2D ILC magnetic semiconductors, tentative theoretical models based on topology for mechanical interpretations, and next-step first-principles research within the domain.

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Functionalization of monolayer MoS2 by substitutional doping: A first-principles study

Cited by 304 publications

References 44 publications

Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

Valley polarization in magnetically doped single-layer transition-metal dichalcogenides

Bandgap tunability at single-layer molybdenum disulphide grain boundaries

Introducing Magnetism into 2D Nonmagnetic Inorganic Layered Crystals: A Brief Review from First-Principles Aspects

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