Electronic and optical properties of nanostructured MoS2 materials: influence of reduced spatial dimensions and edge effects

2017 ◽  
Vol 19 (24) ◽  
pp. 15891-15902 ◽  
Author(s):  
Vladan Mlinar

Theoretical prediction of how the electronic and optical properties of nanostructured MoS2 materials are influenced by reducing spatial dimensions and edge effects is presented. We open pathways for further experimental studies and potential optoelectronic applications.

2020 ◽  
Vol 8 (1) ◽  
pp. 23-28
Author(s):  
Aawzad A. Abdulkareem ◽  
Sarkawt A. Sami ◽  
Badal H. Elias

Plane waves with norm conserving pseudopotentials (PW-PP) method in conjunction with density functional theory (DFT) frame work have been used to investigate structural, electronic and optical properties of lead-halide cubic perovskite CsPbX3 (X=Br, Cl and I). The generalized gradient approximation (GGA), specifically Perdew-Burke-Ernzerhof (PBE) flavor, has been chosen to treat the exchange correlation term of Kohn-Sham equation. Structural parameters are comparable with other theoretical and experimental studies. In spite of good agreement of our band gap values  with other theoretical works, however, they were not comparable when compared to the experimental  values due to the well-known problem of Eg value underestimation of DFT. To update the  value, we have used GW method as a self-consistent quasiparticle method on energies and wave functions and indeed they have been improved. Optical properties have been calculated using density functional perturbation theory (DFPT). Our results show that CsPbX3 (X=Br, Cl, I) has maximum response to the electromagnetic spectrum at low energies (visible region) but minimum response at high energies.


1986 ◽  
Vol 70 ◽  
Author(s):  
S. Y. Lin ◽  
G. Lucovsky ◽  
S. Guha ◽  
J. S. Payson

ABSTRACTThis paper describes a calculation of twofold-coordinated (or divalent) intrinsic bonding defects in a-SiSn:H alloy films. The motivation for this study comes from experimental studies of the electronic and optical properties of a- Si, Sn:H alloys which indicate dramatic changes in the electronic and photoelectronic properties for small concentrations of Sn (approximately 1–2 at. %). We have used a cluster Bethe lattice structural model and an empirical tight-binding Hamiltonian to investigate the electronic properties of tetrahedrally bonded Sn atoms and neutral Sn defect centers (T2o and T3o) and in an a-Si host. We find that: (C) fourfoldcoordinated Sn atoms simply promote a reduction in the optical bandgap, with the energy gap disappearing for Sn concentrations of about 20 to 30 at. %; (2) neutral dangling bonds (T2o) or threefold-coordinated Sn atoms generate a localized state in the gap that is iower in energy than the corresponding neutral Si atom dangling bond; and (3) divalent (T2o) or twofold-coordinated Sn atoms give rise to two states in the gap, an occupied state that is lower in energy that either the Sn or Si dangling bond, and an empty state that is just below the conduction band edge. We show that the electronic and optical properties of the a-SiSn:H alloys can be understood in terms of a model in which there are relatively high densities of unhydrogenated Sn divalent sites and/or Sn dangling bonds.


2020 ◽  
Vol 142 ◽  
pp. 106519 ◽  
Author(s):  
Dat D. Vo ◽  
Tuan V. Vu ◽  
Le C. Nhan ◽  
Chuong V. Nguyen ◽  
Huynh V. Phuc ◽  
...  

2018 ◽  
Vol 47 (16) ◽  
pp. 6101-6127 ◽  
Author(s):  
Hongmei Wang ◽  
Chunhe Li ◽  
Pengfei Fang ◽  
Zulei Zhang ◽  
Jin Zhong Zhang

As a two-dimensional (2D) material, molybdenum disulfide (MoS2) exhibits unique electronic and optical properties useful for a variety of optoelectronic applications including light harvesting.


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