Spin-orbital effects in metal-dichalcogenide semiconducting monolayers

Abstract

Metal-dioxide & metal-dichalcogenide monolayers are studied by means of Density Functional Theory. For an accurate reproduction of the electronic structure of transition metal systems, the spin orbit interaction is considered by using fully relativistic pseudopotentials (FRUP). The electronic and spin properties of MX2 (M = Sc, Cr, Mn, Ni, Mo & W and X = O, S, Se & Te) were obtained with FRUP, compared with the scalar relativistic pseudopotentials (SRUP) and with the available experimental results. Among the differences between FRUP and SRUP calculations are giant splittings of the valence band, substantial band gap reductions and semiconductor to metal or non-magnetic to magnetic “transitions”. MoO2, MoS2, MoSe2, MoTe2, WO2, WS2 and WSe2 are proposed as candidates for spintronics, while CrTe2, with μ ~ 1.59 μB, is a magnetic metal to be experimentally explored.

Band structure and giant Stark effect in two-dimensional transition-metal dichalcogenides

“…In particular, it will aid band-gap and opto-electronic engineers to select the optimal TMDC for their device requirements. [61], 0.45 [22], 0.534 [86], 0.60 [91] 0.34 [53] 0.98 6.25 [53], [24] 0.06 ± 0. 0.00 Mono 0.51 [22], 0.51 [61], 0.561 [86], 0.51 [92] 0.54…”

Eighteen functional monolayer metal oxides: wide bandgap semiconductors with superior oxidation resistance and ultrahigh carrier mobility

“…Previously, the geometric and electronic structures of monolayer GeO, SnO, SnO 2 , MoO 2 , WO 2 , MoO 3 and NiO 2 were studied, [25][26][27][28][29][30] but the carrier mobilities of only MoO 3 and SnO monolayers were reported. 27,29 Here, the carrier transport properties of the MMOs are systematically investigated.…”

“…10 Theoretically, the electronic properties of several monolayer metal oxides (MMOs), such as GeO, SnO, MoO 2 , WO 2 and MoO 3 , with different phases have been studied. [25][26][27][28][29][30] It was found that the bandgap of monolayer MOs decreases with increase of the thickness. Nonmagnetic layered metal oxides could be transformed to magnetic ones with both sides of the layer being functionalized.…”

Epitaxial fabrication of two-dimensional NiSe2 on Ni(111) substrate

“…Moreover, interesting characteristics may be found in 2D TMDs that were unnoticed or nonexistent in their bulk counterparts due to spin-orbit coupling or quantum confinement effects. [18][19][20][21][22][23] For example, when monolayer MoS 2 is cut away from the bulk, it shows an indirect-todirect bandgap transition, making it a promising material for electronic and optoelectronic applications. [24][25][26] Many other 2D TMD materials with outstanding properties and promising applications have also become hot topics of research in recent years.…”