scholarly journals Metallic and intra-band investigation of optical properties for Borophene nano-sheet: a DFT study

2019 ◽  
Vol 10 (1) ◽  
pp. 33-41
Author(s):  
T. Abasi ◽  
A. Boochani ◽  
S. R. Masharian
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Incident Light ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Semiconductor Behavior ◽  
Structure Density ◽  
Theory Framework

AbstractIn this paper, using the density functional theory framework with the FP-LAPW + lo method by GGA approximation, the electronic and optical properties such as band structure, density of states, dielectric function, energy loss function, absorption and reflection have been investigated for borophene nano-sheet. The optical properties of the borophene have been changed as the incident light direction whereas has the metallic and semiconductor behavior, in the borophene sheet and perpendicular light angles, respectively. Therefore, it can be said that the optical properties of this material are anisotropic.

scholarly journals Электронная структура, оптические свойства и поведение под давлением в соединениях CdB-=SUB=-4-=/SUB=-O-=SUB=-7-=/SUB=- и HgB-=SUB=-4-=/SUB=-O-=SUB=-7-=/SUB=-

2018 ◽  
Vol 60 (9) ◽  
pp. 1662
Author(s):  
А.С. Шинкоренко ◽  
В.И. Зиненко ◽  
М.С. Павловский
Keyword(s):  
Phase Transition ◽  
Density Functional Theory ◽  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Functional Theory ◽  
Structural Modifications ◽  
The Density Functional Theory

AbstractAb initio calculations of the structural, electronic, and optical properties of the CdB_4O_7 and HgB_4O_7 tetraborate compounds in three structural modifications with the Pbca , Cmcm , and Pmn 2_1 symmetry have been performed in the framework of the density functional theory using the VASP package. The calculations of the electronic band structure showed that these compounds in all the investigated modifications are dielectrics with a band gap of 2–4 eV. The calculation of the structural properties of the tetraborates under pressure showed that the phase transition between the Pbca and Pmn 2_1 structures in cadmium and mercury tetraborates occurs under pressures of 4.8 and 4.7 GPa, respectively.

scholarly journals A NOVEL FRACTAL GEOMETRY DOPING FOR GRAPHENE NANORIBBON AND THE OPTIMIZATION OF CRYSTAL: A DENSITY FUNCTIONAL THEORY (DFT) STUDY

2020 ◽  
Vol 17 (35) ◽  
pp. 1148-1158
Author(s):  
Mohammed L. JABBAR ◽  
Kadhum J. AL-SHEJAIRY
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Minimum Energy ◽  
Graphene Nanoribbon ◽  
Chemical Doping ◽  
Functional Theory ◽  
Lower Reactivity ◽  
The Density Functional Theory ◽  
Semiconductor Behavior

Chemical doping is a promising route to engineering and controlling the electronic properties of the zigzag graphene nanoribbon (ZGNR). By using the first-principles of the density functional theory (DFT) calculations at the B3LYP/ 6-31G, which implemented in the Gaussian 09 software, various properties, such as the geometrical structure, DOS, HOMO, LUMO infrared spectra, and energy gap of the ZGNR, were investigated with various sites and concentrations of the phosphorus (P). It was observed that the ZGNR could be converted from linear to fractal dimension by using phosphorus (P) impurities. Also, the fractal binary tree of the ZGNR and P-ZGNR structures is a highlight. The results demonstrated that the energy gap has different values, which located at this range from 0.51eV to 1.158 eV for pristine ZGNR and P-ZGNR structures. This range of energy gap is variable according to the use of GNRs in any apparatus. Then, the P-ZGNR has semiconductor behavior. Moreover, there are no imaginary wavenumbers on the evaluated vibrational spectrum confirms that the model corresponds to minimum energy. Then, these results make P-ZGNR can be utilized in various applications due to this structure became more stable and lower reactivity.

First-principles calculations of the structural, elastic, mechanical, electronic and optical properties of monoclinic Hf4CuSi4

2020 ◽  
Vol 34 (06) ◽  
pp. 2050035
Author(s):  
Xia Xu ◽  
Wei Zeng ◽  
Fu-Sheng Liu ◽  
Zheng-Tang Liu ◽  
Qi-Jun Liu
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Elastic Anisotropy ◽  
Structural Parameters ◽  
Functional Theory ◽  
Text Structures ◽  
Structure Density

In this paper, the structural, electronic, elastic, mechanical and optical properties of monoclinic [Formula: see text] are studied using the first-principles density functional theory (DFT). The calculated structural parameters are consistent with the experimental data. The elastic constants of [Formula: see text] structures are calculated, indicating that [Formula: see text] shows mechanical stability and elastic anisotropy. According to the [Formula: see text] and Poisson’s ratio, monoclinic [Formula: see text] shows a brittle manner. The energy band structure, density of states, charge transfers and bond populations are given. And the band structure shows that the material is a metal conductor. Moreover, the optical properties and optical anisotropy of [Formula: see text] are shown and analyzed.

Comparative density functional theory–density functional tight binding study of fullerene derivatives: effects due to fullerene size, addends, and crystallinity on band structure, charge transport and optical properties

2017 ◽  
Vol 19 (41) ◽  
pp. 28330-28343 ◽  
Author(s):  
Amrita Pal ◽  
Lai Kai Wen ◽  
Chia Yao Jun ◽  
Il Jeon ◽  
Yutaka Matsuo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solid State ◽  
Band Structure ◽  
Charge Transport ◽  
Density Functional ◽  
Tight Binding ◽  
Functional Theory ◽  
Fullerene Derivatives ◽  
Derivatives Of

Comparative DFT–DFTB study of multiple derivatives of C60 and C70 with different addends, in molecular and solid state.

Electronic Structure and Optical Properties of Cu-Doped SnO2

2014 ◽  
Vol 716-717 ◽  
pp. 20-23
Author(s):  
Min Xu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Electronic Structure ◽  
Optical Absorption ◽  
Band Structure ◽  
Density Functional ◽  
Density Of State ◽  
Functional Theory ◽  
Reflectivity Spectrum

based on Density Functional Theory, we investigated the optical structures and the electronic properties of Cu doped SnO2with density of 12.5%, including band structure, the density of state (dos), Dielectric function and optical absorption spectrum. The results show that Fermi level access conduction band gradually with the doped density. It has enhanced the electrical and metal property of material. The peaks of reflectivity spectrum and absorption spectrum correspond density of state.

scholarly journals Substantial Variations in the Optical Absorption and Reflectivity of Graphene When the Concentrations of Vacancies and Doping with Fluorine, Nitrogen, and Oxygen Change

2021 ◽  
Vol 22 (13) ◽  
pp. 6832
Author(s):  
Ali Fransuani Jiménez-González ◽  
Juan Manuel Ramírez-de-Arellano ◽  
Luis Fernando Magaña
Keyword(s):  
Density Functional Theory ◽  
Optical Absorption ◽  
Band Structure ◽  
Numerical Simulations ◽  
Ab Initio ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Density Values

We performed ab initio numerical simulations with the density functional theory to investigate the variations in the band structure, optical absorption, and the reflectivity of vacancy-graphene doped with nitrogen, oxygen, and fluorine for different densities. We considered the density values 0.78%, 1.02%, 1.39%, 2.00%, 3.12%, 5.55%, and 12.5% for the vacancies and doping. In the infrared and visible ranges for all cases, vacancies included, there is a substantial increment in the absorption and reflectivity concerning graphene. The most significant changes are for fluorine and oxygen at a concentration of 12.5%.

scholarly journals Optical Properties of DMA-π-DCV Derivatives: A Theoretical Inspection under the DFT Microscope

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Joaquín Calbo
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Test System ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Donor Acceptor ◽  
Derivatives Of ◽  
Bridge Length ◽  
Theory Framework

The optical properties of a series of donor-acceptor N,N-dimethylaniline-π-dicyanovinylene (DMA-π-DCV) chromophores have been investigated under the density functional theory framework. Focus has been made on the low-lying charge-transfer (CT) electronic transitions for which experimental data is available. The effect of theπ-conjugated bridge length and type was analysed between the families of oligoene and oligoyne derivatives of increasing size. Theoretical calculations demonstrate that the ethylene bridge is a betterπ-communicator and allows for more delocalized frontier molecular orbitals compared to the acetylene spacer. TheΛdiagnostic test allowed rationalization of the orbital spatial overlap in the main CT excitations. The performance of different density functional rungs was assessed in the prediction of the lowest-lying CT electronic transition. Surprisingly, most modern long-range corrected functionals demonstrated to provide among the largest errors, whereas hybrid functionals showed the best performance. Solvatochromism was confirmed in both oligoene and oligoyne compounds. A donor-acceptor-donor triad based on tetrathiafulvalene was utilised as a test system for the prediction of its two CT bands of different nature, energy, and intensity. The hybrid PBE0 (or a similar hybrid analogue) consolidates as the best choice for the prediction of CT excitations in the DMA-π-DCV push-pull family.

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