First-principles study on the electronic structure and optical properties of GaAs nanowires

2015 ◽  
Vol 29 (04) ◽  
pp. 1550014 ◽  
Author(s):  
Xiang-Hai Wei ◽  
Tao Gao ◽  
Lei Wan ◽  
Peng-Fei Lu
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Peak Position ◽  
Large Radius ◽  
Complex Dielectric Function ◽  
Optical Reflectivity ◽  
Gaas Nanowires

The electronic structure and optical properties of wurtzite gallium arsenide (GaAs) nanowires (NWs) are investigated within the first-principles plane-wave pseudo-potential method based on the density functional theory (DFT). The calculated results show that GaAs NWs are direct band gap semiconductor and demonstrate the achievement of p-type behavior. These NWs of the electronic behavior transitions from semiconductor to metal after hydrogen-passivated. The complex dielectric function, absorption coefficient and optical reflectivity are calculated and the peak position distributions of imaginary parts of the complex dielectric function have been explained. We may conclude GaAs NWs belongs to what crystal system through the dielectric tensors. Optical reflectivity is obtained and the peak position distributions of imaginary parts of the complex dielectric function have been explained, and their absorption spectra are sensitive to the large radius of GaAs NWs.

First-principles study of electronic and optical properties of Sr2ZnN2 under pressure

2016 ◽  
Vol 30 (10) ◽  
pp. 1650139
Author(s):  
Kai Liang ◽  
Hui Zhao
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Electronic Structure ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Optical Transition ◽  
Dft Method ◽  
Structural Parameter ◽  
Generalized Gradient

First-principles calculations of ternary Sr2ZnN2 compound using density-functional theory (DFT) method within the generalized gradient approximation (GGA) has been performed. Based on the optimized structural parameter, the electronic properties and optical properties have been researched. The calculated lattice constants are in agreement with the experimental and theoretical results. The electronic structure have been investigated throughout the calculated band structure and density of states (DOS). It shows that this compound belongs to the semiconductors with a band gap of about 0.775[Formula: see text]eV. Furthermore, in order to clarify the optical transition of this material, the optical properties such as dielectric function, absorption coefficient, reflectivity, refractive index and energy-loss function at different pressures of 0, 10 and 20[Formula: see text]GPa in the energy range 0–20[Formula: see text]eV were performed and discussed. It shows that Sr2ZnN2 is a strong anisotropy material and the imaginary part of dielectric function shifts to higher energy region as the pressure increases. The square of calculated static refractive index is equal to static dielectric function, which corresponds to the theory formula. In conclusion, pressure is a effective method to change the electronic structure and optical properties.

First Principles Calculations of Electronic Structure and Optical Properties of Cu-Doped SnS2

2013 ◽  
Vol 373-375 ◽  
pp. 1965-1969
Author(s):  
Kun Nan Qin ◽  
Ling Zhi Zhao ◽  
Yong Mei Liu ◽  
Fang Fang Li ◽  
Chao Yang Cui
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Optical Absorption Coefficient ◽  
Impurity Level ◽  
First Principles Calculations ◽  
Absorption Region ◽  
Functional Theory ◽  
The Density Functional Theory

The electronic structure and optical properties of Cu-doped SnS2with Sn-substituted content of 0, 12.5 and 37.5 at.% were successfully calculated by the first principles plane-wave pseudopotentials based on the density functional theory. It is found that the intermediate belts appear near the Fermi level and the energy band gap becomes narrower after the doping of the Cu atoms. The absorption peaks show a remarkable redshift and the absorption region broadens relatively after introducing acceptor impurity level. When Sn atoms of 37.5 at% were substituted by Cu, the optical absorption coefficient is significantly improved in the frequency range below 5.58 eV and over 8.13 eV.

Electronic Structure, Effective Masses and Optical Properties of Monoclinic HfO2 from First-Principles Calculations

2011 ◽  
Vol 216 ◽  
pp. 341-344 ◽  
Author(s):  
Qi Jun Liu ◽  
Zheng Tang Liu ◽  
Li Ping Feng
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Effective Masses ◽  
Indirect Band Gap ◽  
Calculated Equilibrium

Electronic structure, effective masses and optical properties of monoclinic HfO2were studied using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT). The calculated equilibrium lattice parameters are in agreement with the previous works. From the band structure, the effective masses and optical properties are obtained. The calculated band structure shows that monoclinic HfO2has indirect band gap and all of the effective masses of electrons and holes are less than that of a free electron. The peaks position distributions of imaginary parts of the complex dielectric function have been explained according to the theory of crystal-field and molecular-orbital bonding.

Investigation of optical properties of Zn1-xVxO (x = 0.0, 0.125, 0.25, 0.5) by first principles calculations

2014 ◽  
Vol 28 (31) ◽  
pp. 1450243
Author(s):  
R. Taghavi Mendi ◽  
S. M. Elahi ◽  
M. R. Abolhassani
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Full Potential ◽  
First Principles Calculations ◽  
Generalized Gradient ◽  
Electron Model ◽  
Low Energies

In this paper, some optical properties of Zn 1-x V x O (0 ≤ x ≤ 0.5) such as real and imaginary part of dielectric function, energy loss function, plasmon energies and refractive index are investigated by first principles calculations. The calculations were performed in density functional theory (DFT) framework using full potential linear augmented plane wave (FP-LAPW) and generalized gradient approximation (GGA). Analysis of dielectric function shows that by substituting V instead of Zn in Zn 1-x V x O , static dielectric function, absorption and anisotropy at low energies are increased. The investigations show that V doping in ZnO affects plasmon energies. The plasmon energies have been compared with free electron model. The calculated plasmon energy for pure ZnO is nearly close to other works. The refractive index at low energies is increased significantly, so that V -doped ZnO can be used as a high refractive material.

Electronic and optical properties of AlN under pressure: DFT calculations

2017 ◽  
Vol 31 (02) ◽  
pp. 1650255
Author(s):  
Sahar Javaheri ◽  
Arash Boochani ◽  
Manuchehr Babaeipour ◽  
Sirvan Naderi
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Dielectric Function ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
Zinc Blende ◽  
Rocksalt Phase ◽  
Optical And Electronic Properties ◽  
Theoretical Results

Structural, elastic, optical, and electronic properties of wurtzite (WZ), zinc-blende (ZB), and rocksalt (RS) structures of AlN are investigated using the first-principles method and within the framework of density functional theory (DFT). Lattice parameters, bulk modulus, shear modulus, Young’s modulus, and elastic constants are calculated at zero pressure and compared with other experimental and theoretical results. The wurtzite and zinc-blende structures have a transition to rocksalt phase at the pressures of 12.7 GPa and 14 GPa, respectively. The electronic properties are calculated using both GGA and EV-GGA approximations; the obtained results by EV-GGA approximation are in much better agreement with the available experimental data. The RS phase has the largest bandgap with an amount of 4.98 eV; by increasing pressure, this amount is also increased. The optical properties like dielectric function, energy loss function, refractive index, and extinction coefficient are calculated under pressure using GGA approximation. Inter-band transitions are investigated using the peaks of imaginary part of the dielectric function and these transitions mainly occur from N-2[Formula: see text] to Al-3[Formula: see text] levels. The results show that the RS structure has more different properties than the WZ and ZB structures.

Effects of rare earth adsorption on electronic structure and optical properties in β-Si3N4 ceramics from first principles

RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 53570-53574 ◽  
Author(s):  
Yin Wei ◽  
Hongjie Wang ◽  
Xuefeng Lu ◽  
Jiangbo Wen ◽  
Min Niu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Rare Earth ◽  
Silicon Nitride ◽  
Rare Earths ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
Si3n4 Ceramics

Electronic structure and optical properties of silicon nitride adsorbed by rare earths are explored by density functional theory.

scholarly journals Electronic structure and optical properties of CsI under high pressure: a first-principles study

RSC Advances ◽  
2017 ◽  
Vol 7 (83) ◽  
pp. 52449-52455 ◽  
Author(s):  
Qiang Zhao ◽  
Zheng Zhang ◽  
Xiaoping Ouyang
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Calculation Method ◽  
Density Functional ◽  
First Principles Calculation ◽  
Functional Theory ◽  
First Principles Study

We investigated the effects of high pressure on the electronic structure and optical properties of a CsI crystal through a first-principles calculation method based on density functional theory.

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.

scholarly journals First Principles Study on the Electronic Structure and Optical Properties of La Doped YB6 Crystals

2021 ◽  
pp. X
Author(s):  
Hongbo TANG ◽  
Qiuyue LI ◽  
Jian ZHOU ◽  
Lihua XIAO ◽  
Ping PENG
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Near Infrared ◽  
Infrared Light ◽  
First Principles Calculations ◽  
Functional Theory ◽  
La Doped

Received 03 January 2020; accepted 17 June 2020 We have investigated the optical properties of La (0, 0.125, 0.250) doped YB6 by means of first-principles calculations within the framework of density functional theory. It was found that electronic and optical properties of YB6 crystals varied remarkably when Y atoms were replaced with La atoms. Furthermore, with increasing content of La in YB6 crystals from 12.5 % to 25 % reflectivity and absorption coefficient of near infrared light decreased obviously, while the transmittance was enhanced.

Influence of Nd-Doping on Electronic Structure and Optical Properties of ZnO

2014 ◽  
Vol 941-944 ◽  
pp. 658-661
Author(s):  
Lan Li Chen ◽  
Hong Duo Hu ◽  
Zhi Hua Xiong
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Conduction Band ◽  
First Principles ◽  
Energy Region ◽  
Lower Energy ◽  
Density Functional ◽  
Functional Theory ◽  
Level Shifts ◽  
Lower Energy Region

A detailed first-principles study of electronic structure and optical properties of Nd-doping ZnO with various concentrations of Nd was performed using density functional theory. The results show that the band gap of Nd-doping ZnO slightly widens with the increasing Nd concentration, this is because the conduction band undergoes a greater shift toward the lower-energy region than the valence band, which is agreement with experimental results. Furthermore, in comparison to pure-ZnO, the Fermi level shifts into the conduction band after Nd-doping ZnO. And the calculated result of imaginary part of dielectric function of Nd-doping ZnO shows that there is a sharp peak in the lower-energy region, which is due to the electrons transition between d-d orbital of Nd atom.

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