Electronic Properties of Triangle Molybdenum Disulfide (MoS2) Clusters with Different Sizes and Edges

Abstract

The electronic structures and transition properties of three types of triangle MoS2 clusters, A (Mo edge passivated with two S atoms), B (Mo edge passivated with one S atom), and C (S edge) have been explored using quantum chemistry methods. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of B and C is larger than that of A, due to the absence of the dangling of edge S atoms. The frontier orbitals (FMOs) of A can be divided into two categories, edge states from S3p at the edge and hybrid states of Mo4d and S3p covering the whole cluster. Due to edge/corner states appearing in the FMOs of triangle MoS2 clusters, their absorption spectra show unique characteristics along with the edge structure and size.

Electronic, Optical, and Magnetic Properties of Doped Triangular MoS2 Quantum Dots: A Density Functional Theory Approach

“…Also, values of the refractive index in static conditions and when the photon energy is are reported. Similar QDs were studied [ 45–47 ] but differing essentially with regard to edge termination, and resulting in a decreasing of the HOMO–LUMO gaps as the dot size augments; the same trend found here, but with larger gap magnitudes. These results are explained by the different edge states appearing in each case, due to the distinct atomic edge terminations.…”

“…As it has been discussed in the literature, these energies correspond to edge states and this is revealed in the reported plots of partial charge density for different dot geometries. [41,42,44,47,48] Refraction index was calculated in the range 0 À 20 eV. Here, we are reporting its values at zero frequency and for a photon energy of 2.1 eV for x-polarized light (y-polarized results follow the same trend and are very close in magnitude) (see Table 1).…”

“…As it has been discussed in the literature, these energies correspond to edge states and this is revealed in the reported plots of partial charge density for different dot geometries. [ 41,42,44,47,48 ]…”

“…Theoretical research on electronic properties of MoS 2 and other TMDQDs has included tight‐binding (TB), [ 41–43 ] first‐principles density functional (DFT) theory [ 44–48 ] approaches, for different geometrical structures such as triangular and hexagonal. Several proposals for a Slater–Koster TB description of TMD MLs and multilayers appeared in 2013.…”

Electrodeposition of Molybdenum Disulfide (MoS2) Nanoparticles on Monocrystalline Silicon

“…In fact, bulk MoS 2 is an indirect semiconductor with a band gap of 1.2 eV [ 8 ], whereas its single-layered form shows a direct gap of 1.8 eV [ 6 , 9 ], enabling the production of switchable transistors [ 4 , 5 ] and photodetectors [ 4 , 10 ]. In particular, the 2D layered structure of MoS 2 has interesting optical–electronic features that significantly differ from those in the bulk form [ 11 , 12 ]. Two-dimensional layered MoS 2 has recently attracted great interest in the field of supercapacitors since it presents a sheet-like morphology and large in-plane conductivity.…”