Band structure ofMoS2,MoSe2,a

Abstract

In this work the complete valence-band structure of the molybdenum dichalcogenides MoS 2 , MoSe 2 , and ␣-MoTe 2 is presented and discussed in comparison. The valence bands have been studied using both angleresolved photoelectron spectroscopy ͑ARPES͒ with synchrotron radiation, as well as ab initio band-structure calculations. The ARPES measurements have been carried out in the constant-final-state ͑CFS͒ mode. The results of the calculations show in general very good agreement with the experimentally determined valenceband structures allowing for a clear identification of the observed features. The dispersion of the valence bands as a function of the perpendicular component k ជ Ќ of the wave vector reveals a decreasing three-dimensional character from MoS 2 to ␣-MoTe 2 which is attributed to an increasing interlayer distance in the three compounds. The effect of this k ជ Ќ dispersion on the determination of the exact dispersion of the individual states as a function of k ជ ʈ is discussed. By performing ARPES in the CFS mode the k ជ ʈ component for off-normal emission spectra can be determined. The corresponding k ជ Ќ value is obtained from the symmetry of the spectra along the ⌫A, KH, and M L lines, respectively.

Density functional study of the adsorption and van der Waals binding of aromatic and conjugated compounds on the basal plane of MoS2

“…The calculated equilibrium lattice constant of a = 3.235 Å compares well to the experimental lattice constant of 3.16 Å. 34 A plane-wave cutoff of 30 Ry and a density cutoff of 60 Ry are employed using the double-grid technique. 35 Ultrasoft pseudopotentials are used except for sulfur, where a soft pseudopotential is employed.…”

Electroluminescence in Single Layer MoS2

“…A single layer of MoS 2 (1L-MoS 2 ) consists of two planes of hexagonally arranged S atoms linked to a hexagonal plane of Mo atoms via covalent bonds [3,[6][7][8][9]. In the bulk, individual MoS 2 layers are held together by weak van der Waals forces [6][7][8][9].…”

“…A single layer of MoS 2 (1L-MoS 2 ) consists of two planes of hexagonally arranged S atoms linked to a hexagonal plane of Mo atoms via covalent bonds [3,[6][7][8][9]. In the bulk, individual MoS 2 layers are held together by weak van der Waals forces [6][7][8][9]. This property has been exploited in lubrication technology [10] and, more recently, has lead to the isolation of 1L-MoS 2 [2][3][4]11].…”

Ising superconductivity and Majorana fermions in transition-metal dichalcogenides

“…Monolayer transition metal dichalcogenides (TMDs) are two-dimensional materials composed of a layer of triangularly arranged transition metal atoms sandwiched between two layers of triangularly arranged chalcogenide atoms, forming a 2D honeycomb lattice similar to graphene but with broken sublattice symmetry [1,2]. With their strong mechanical properties, relatively high electron mobility, and the massive Dirac energy spectrum [3,4], monolayer TMDs are considered potential materials for next generation transistors [5][6][7][8][9].…”