Electrical and optical properties of Si-doped Ga2O3

2017 ◽  
Vol 31 (15) ◽  
pp. 1750172 ◽  
Author(s):  
Yin Li ◽  
Chuanghua Yang ◽  
Liyuan Wu ◽  
Ru Zhang
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Hybrid Functional ◽  
Charge Densities ◽  
Conduction Bands ◽  
The Density Functional Theory ◽  
Si Doped ◽  
Valence Bands ◽  
Structure Density

The charge densities, band structure, density of states, dielectric functions of Si-doped [Formula: see text]-Ga2O3 have been investigated based on the density functional theory (DFT) within the hybrid functional HSE06. The heavy doping makes conduction band split out more bands and further influences the band structure. It decreases the band gap and changes from a direct gap to an indirect gap. After doping, the top of the valence bands is mainly composed by the O-2p states, Si-3p states and Ga-4p states and the bottom of the conduction bands is almost formed by the Si-3s, Si-3p and Ga-4s orbits. The anisotropic optical properties have been investigated by means of the complex dielectric function. After the heavy Si doping, the position of absorption band edges did not change much. The slope of the absorption curve descends and indicates that the absorption became more slow for Si-doped [Formula: see text]-Ga2O3 than undoped one due to the indirect gap of Si-doped [Formula: see text]-Ga2O3.

Effects of Si Doping on the Structural, Electronic and Optical Properties of Barium Chalcogenide BaS: A First-Principles Study

SPIN ◽  
2020 ◽  
Vol 10 (02) ◽  
pp. 2050014
Author(s):  
H. Absike ◽  
H. Labrim ◽  
B. Hartiti ◽  
H. Ez-Zahraouy
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Original Structure ◽  
Functional Theory ◽  
Electron Charge Density ◽  
Electronic And Optical Properties ◽  
Charge Densities ◽  
The Density Functional Theory ◽  
Si Doped

In this work, the structural, electronic and optical properties of Si-doped barium chalcogenide [barium sulfide (BaS)] with different Si concentrations ([Formula: see text]) are investigated by the first-principles calculations based on the density functional theory (DFT). The band structures, charge densities and complex dielectric functions of the pure as well as Si-doped BaS were presented and analyzed in detail using TB-mBJ approach by WIEN2k package. It is found that silicon concentration can control the bandgap by reducing it to values around 1.4[Formula: see text]eV and 1.6[Formula: see text]eV for 12.5% and 6.25% of Si-doped BaS, respectively. The electron charge density indicates the ionic bonding between silicon and sulfur atoms due to the high electronegativity between them. In fact, the results show that the absorption peaks of Si-doped BaS are enhanced compared with pure BaS. These results suggest that the Ba[Formula: see text]SixS original structure displays excellent physical properties thereby revealing that it is a promising material in advanced optoelectronic and solar cell applications.

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.

Electronic and optical properties of zinc-blende GeC by first principles study

2015 ◽  
Vol 29 (20) ◽  
pp. 1550103
Author(s):  
Jinhui Zhai ◽  
Jinguang Zhai ◽  
Ajun Wan
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Dielectric Constants ◽  
Electronic And Optical Properties ◽  
Optical Functions ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
Valence Bands ◽  
Energy Dependent

The electronic and optical properties of zinc-blende (zb)[Formula: see text]GeC have been investigated using first principles calculations based on the density functional theory (DFT). The obtained band gap of zb–GeC is 2.30[Formula: see text]eV by means of Heyd–Scuseria–Ernzerhof (HSE) functional. We have discussed the energy-dependent optical functions including dielectric constants, refractive index, absorption, reflectivity, and energy-loss spectrum in detail. The results reveal that zb–GeC has a higher static dielectric constant compared with that of zb–SiC. The optical functions are mainly associated with the interband transitions from the occupied valence bands (VBs) Ge[Formula: see text][Formula: see text] and C[Formula: see text][Formula: see text] states to Ge[Formula: see text][Formula: see text], [Formula: see text] and C[Formula: see text][Formula: see text] states of the unoccupied conduction bands (CBs).

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.

scholarly journals Cu-Doped KCl Unfolded Band Structure and Optical Properties Studied by DFT Calculations

2020 ◽  
Author(s):  
Cesar Castillo-Quevedo ◽  
Jose Luis Cabellos ◽  
Raul Aceves ◽  
Roberto Núñez-González ◽  
Alvaro Posada-Amarillas
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Copper Ions ◽  
Point Of View ◽  
Basis Set ◽  
Theoretical Point ◽  
Conduction Bands ◽  
Cu Substitution ◽  
Effect Of Copper

The unfolded band structure and optical properties of Cu-doped KCl crystals were computed by first principles within the framework of density functional theory, implemented in the ABINIT electronic structure package utilizing pseudopotential approximation and a plane-wave basis set. From a theoretical point of view, Cu substitution into pristine KCl crystals requires calculation by the supercell (SC) method. This procedure shrinks the Brillouin zone, resulting in a folded band structure that is difficult to interpret. To solve this problem and gain insight into the effect of copper ions (Cu+) on electronic properties, the band structure of SC KCl:Cu was unfolded to make a direct comparison with the band structure of the primitive cell (PC) of pristine KCl. To understand the effect of Cu substitution on optical absorption, we calculated the imaginary part of the dielectric function of KCl:Cu through a sum-over-states formalism and broke it down into different band contributions by partially making an iterated cumulative sum (ICS) of selected valence and conduction bands. Consequently, we identified those interband transitions that give rise to the absorption peaks due to the Cu+ ion. These transitions involve valence and conduction bands formed by the Cu-3d and Cu-4s electronic states

First-principles study on electronic structure and optical properties of In-doped GaN

2014 ◽  
Vol 13 (08) ◽  
pp. 1450070 ◽  
Author(s):  
Xingxiang Ruan ◽  
Fuchun Zhang ◽  
Weihu Zhang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Visible Region ◽  
Solar Spectrum ◽  
Potential Method ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Density

The In -doped GaN is investigated by first-principles calculations of plane wave ultra-soft pseudo-potential method based on the density functional theory (DFT). The band structure, electronic structure, density of states and optical properties are investigated. The results indicate that the band-gap becomes narrower and the absorption edge of optical properties is red-shifted with the increase in In -doped concentration. Meanwhile, the visible region has strong absorption properties, and the significant absorption peaks are observed near 3.0 eV and 6.1 eV. The other peaks correspond to the wavelength of absorption spectra from the ultraviolet portion extending to the infrared portion, which almost covers the entire solar spectrum. The studied results show that In -doped GaN can be applied as solar cell and transparent conductivity material.

First Principles Study on Magnetic and Optical Properties of Single Layer CrSi2

2018 ◽  
Vol 787 ◽  
pp. 53-59
Author(s):  
Shao Bo Chen ◽  
Kai Li Yao ◽  
Ping Huang ◽  
Ze Lan Jiang ◽  
Shi Lian Lv ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Vacuum Ultraviolet ◽  
Single Layer ◽  
Far Infrared ◽  
Potential Method ◽  
Ultraviolet Region ◽  
The Density Functional Theory ◽  
Structure Density ◽  
Far Ultraviolet

According to first-principle based on the density functional theory, the magnetic and optical properties of single layer CrSi2are calculated and analyzed by plane wave pseudo potential method. The band structure, density of state, optical absorption spectra, reflectivity and energy loss function of single layer CrSi2are obtained. The results show that single layer CrSi2has the properties of metal and magnetism. The calculations of optical properties of single layer CrSi2material deduce that it can absorb photons which belong to visible to ultraviolet region, even in far-infrared and far-ultraviolet regions. Single layer CrSi2has a good optical permeability to photon (with energy from 13 to 40eV), which shows that single layer CrSi2is suitable for optoelectronic devices, especially in infrared and vacuum ultraviolet detection applications.

scholarly journals Simplicity Out of Complexity: Band Structure for W20O58 Superconductor

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
A.A. Slobodchikov ◽  
I.A. Nekrasov ◽  
N.S. Pavlov ◽  
M.M. Korshunov
Keyword(s):  
Band Structure ◽  
Density Functional ◽  
Tight Binding ◽  
Low Energy ◽  
Spin Projection ◽  
Generalized Gradient ◽  
Binding Model ◽  
Real Crystal ◽  
The Density Functional Theory ◽  
Structure Density

The band structure, density of states, and the Fermi surface of a recently discovered superconductor, oxygen-deficient tungsten oxide WO2.9 that is equivalent to W20O58, is studied within the density functional theory (DFT) in the generalized gradient approximation (GGA). Here we show that despite the extremely complicated structure containing 78 atoms in the unit cell, the low-energy band structure is quite feasible. Fermi level is crossed by no more than 10 bands per one spin projection (and even 9 bands per pseudospin projection when the spin-orbit coupling is considered) originating from the t2g 5d-orbitals of tungsten atoms forming zigzag chains. These bands become occupied because of the specific zigzag octahedra distortions. To demonstrate the role of distortions, we compare band structures of W20O58 with the real crystal structure and with the idealized one. We also propose a basis for a minimal low-energy tight-binding model for W20O58.

First-principles studies of the electronic structure and optical properties of AgBO3 (B=Nb,Ta) in the paraelectric phase

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Suleyman Cabuk ◽  
Sevket Simsek
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Local Density ◽  
Theoretical Data ◽  
Electronic Energy ◽  
Cubic Phase ◽  
Structure Density ◽  
First Time ◽  
Electron Energy Loss

AbstractThe electronic energy-band structure, density of states (DOS), and optical properties of AgBO3 in the paraelectric cubic phase have been studied by using density functional theory within the local density approximation for exchange-correlation for the first time. The band structure shows a band gap of 1.533 eV (AgNbO3)and 1.537 eV (AgTaO3)at (M-⌈)point in the Brillouin zone. The optical spectra of AgBO3 in the photon energy range up to 30 eV are investigated under the scissor approximation. The real and imaginary parts of the dielectric function and — thus the optical constants such as reflectivity, absorption coefficient, electron energy-loss function, refractive index, and extinction coefficient — are calculated. We have also made some comparisons with related experimental and theoretical data that is available.

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.

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