Publications by authors named "Nguyen Thi Han"

Article Synopsis
  • Doping two-dimensional (2D) materials, like the HfO monolayer, with transition metals (Mn and Fe) and nonmetals (B and C) alters their electronic and magnetic properties, making them useful for spintronic applications.
  • The pristine HfO monolayer is nonmagnetic with a large band gap, but doping introduces magnetism; Mn and Fe doping leads to total magnetic moments of 3.00 and 4.00, whereas B and C impact the system's electronic characteristics.
  • Pairing transition metals with nonmetal elements results in a magnetic semiconductor nature; however, these paired systems have smaller magnetic moments compared to single dopants, signifying a complex relationship between doping
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We employed Density Functional Theory (DFT) to investigate the electronic, magnetic, and optical characteristics of armchair graphene nanoribbons (AGNRs) decorated with neptunium (Np) and plutonium (Pu). Our analysis delves deeply into the intricate orbital hybridizations associated with C-Np, C-Pu, C-C, Np-Np, and Pu-Pu chemical bonds. Through this approach, we explore the electronic band structure, band-decomposed charge densities, spin-charge distributions, and Van Hove singularities in the density of states.

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By using first-principles calculations, we have studied the electronic and optical characteristics of group III-nitrides, such as BN, AlN, GaN, and InN monolayers. The optimized geometry, quasi-particle energy spectra, charge density distributions, band-decomposed charge densities, and Van Hove singularities in density of states are described in the work using physical and chemical pictures and orbital hybridizations found in B-N, Al-N, Ga-N, and In-N chemical bonds. Moreover, the dielectric functions, energy loss functions, absorption coefficients, and reflectance spectra with electron-hole interactions of optical properties are successfully achieved.

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Our study focused on exploring the electronic and optical characteristics of the GaGeTe monolayer using first-principles calculations. Our findings showed that this material has remarkable physical and chemical properties attributed to its unique band structure, van Hove singularities in the density of states (DOS), charge density distributions, and charge density differences. We also observed excitonic effects, multiple optical excitation peaks, and strong plasmon modes in the energy loss functions, absorption coefficients, and reflectance spectra, which contribute to its enriched optical response.

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We investigate the geometric, electric, and optical properties of two-dimensional honeycomb lattices using first-principles simulations. The main focus of this work is on the similarities and differences in their characteristics, as well as the delicate connection of orbital hybridizations and spin-polarizations with electronic and optical properties. Graphene, silicene, germanene, and their semi-hydrogenated systems, in turn, display sp, sp-sp, and sps hybridizations.

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We perform the electronic and optical properties of the LiPSCl compound using first-principles calculation. The featured physical and chemical pictures and orbital hybridizations in all Li-S and P-S chemical bonds are clearly exhibited, such as the optimized geometry, the quasi-particle energy spectra, the band-decomposed charge densities, and the van Hove singularities in the density of states. Furthermore, the calculated results of the presence and absence of electron-hole interactions in optical responses are achieved successfully through the dielectric function, the energy loss functions, the absorption coefficients, and the reflectance spectra.

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We used first-principles calculations to investigate the electrical and optical properties of CsGeX (X = Cl, Br, and I) compounds. These materials present rich and unique physical and chemical phenomena, such as the optimal geometric structure, the electronic band structure, the charge density distribution, and the special van Hove singularities in the electronic density of states. The optical properties cover a slight red shift of the optical gap, corresponding to weak electron-hole interactions, strong absorption coefficients, and weak reflectance spectra.

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The three-dimensional ternary LiFeO compound presents various unusual properties. The main features are thoroughly explored by using many-body perturbation theory. The concise physical/chemical picture, the critical spin polarizations, and orbital hybridizations in the Li-O and Fe-O bonds are clearly examined through geometric optimization, quasi-particle energy spectra, spin-polarized density of states, spatial charge densities, spin-density distributions, and strong optical responses.

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LiSiO compound exhibits unique electronic and optical properties. The state-of-the-art analyses, which based on first-principle calculations, have successfully confirmed the concise physical/chemical picture and the orbital bonding in Li-O and Si-O bonds. Especially, the unusual optical response behavior includes a large red shift of the onset frequency due to the extremely strong excitonic effect, the polarization of optical properties along three-directions, various optical excitations structures and the most prominent plasmon mode in terms of the dielectric functions, energy loss functions, absorption coefficients and reflectance spectra.

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The three-dimensional ternary LiGeO compound presents various unusual essential properties. The main features are thoroughly explored from the first-principles calculations. The concise pictures, the critical orbital hybridizations in Li-O and Ge-O bonds, are clearly examined through the optimal geometric structure, the atom-dominated electronic energy spectrum, the spatial charge densities, the atom and orbital-decomposed van Hove singularities, and the strong optical responses.

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Lithium metasilicate (LiSiO), which could serve as the electrolyte material in Li-based batteries, exhibits unique lattice symmetry (an orthorhombic crystal), valence and conduction bands, charge density distribution, and van Hove singularities. Delicate analyses, based on reliable first-principles calculations, are utilized to identify the critical multi-orbital hybridizations in Li-O and Si-O bonds, 2s-(2s, 2p , 2p , 2p ) and (3s, 3p , 3p , 3p )-(2s, 2p , 2p , 2p ), respectively. This system shows a huge indirect gap of 5.

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