scholarly journals Electro-Optical Properties of Monolayer and Bilayer Pentagonal BN: First Principles Study

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 440 ◽  
Author(s):  
Mehran Amiri ◽  
Javad Beheshtian ◽  
Farzaneh Shayeganfar ◽  
Mahdi Faghihnasiri ◽  
Rouzbeh Shahsavari ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Electronic Band Structure ◽  
Hexagonal Boron Nitride ◽  
Visible Absorption ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Photovoltaic Application ◽  
Spin Polarized ◽  
3D Networks

Two-dimensional hexagonal boron nitride (hBN) is an insulator with polar covalent B-N bonds. Monolayer and bilayer pentagonal BN emerge as an optoelectronic material, which can be used in photo-based devices such as photodetectors and photocatalysis. Herein, we implement spin polarized electron density calculations to extract electronic/optical properties of mono- and bilayer pentagonal BN structures, labeled as B 2 N 4 , B 3 N 3 , and B 4 N 2 . Unlike the insulating hBN, the pentagonal BN exhibits metallic or semiconducting behavior, depending on the detailed pentagonal structures. The origin of the metallicity is attributed to the delocalized boron (B) 2p electrons, which has been verified by electron localized function and electronic band structure as well as density of states. Interestingly, all 3D networks of different bilayer pentagonal BN are dynamically stable unlike 2D structures, whose monolayer B 4 N 2 is unstable. These 3D materials retain their metallic and semiconductor nature. Our findings of the optical properties indicate that pentagonal BN has a visible absorption peak that is suitable for photovoltaic application. Metallic behavior of pentagonal BN has a particular potential for thin-film based devices and nanomaterial engineering.

Ab-Initio Investigation of Strain Effects on the Physical Properties of PdVTe Alloy

2021 ◽  
Author(s):  
Khodja Djamila ◽  
Djaafri Tayeb ◽  
Djaafri Abdelkader ◽  
Bendjedid Aicha ◽  
Hamada Khelifa ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Of States ◽  
Phonon Dispersion ◽  
Electronic Band Structure ◽  
Debye Model ◽  
Full Potential ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Strain Effects ◽  
Half Metallic

The investigations of the strain effects on magnetism, elasticity, electronic, optical and thermodynamic properties of PdVTe half-Heusler alloy are carried out using the most accurate methods to electronic band structure, i.e. the full-potential linearized augmented plane wave plus a local orbital (FP-LAPW + lo) approach. The analysis of the band structures and the density of states reveals the Half-metallic behavior with a small indirect band gap Eg of 0.51 eV around the Fermi level for the minority spin channels. The study of magnetic properties led to the predicted value of total magnetic moment µtot = 3µB, which nicely follows the Slater–Pauling rule µtot = Zt -18. Several optical properties are calculated for the first time and the predicted values are in line with the Penn model. It is shown from the imaginary part of the complex dielectric function that the investigated alloy is optically metallic. The variations of thermodynamic parameters calculated using the quasi-harmonic Debye model, accord well with the results predicted by the Debye theory. Moreover, the dynamical stability of the investigated alloy is computed by means of the phonon dispersion curves, the density of states, and the formation energies. Finally, the analysis of the strain effects reveals that PdVTe alloy preserves its ferromagnetic half metallic behavior, it remains mechanically stable, the ionic nature dominates the atomic bonding, and the thermodynamic and the optical properties keep the same features in a large interval of pressure.

First Principles Calculations of Electronic Band Structure and Optical Properties of Cr-Doped ZnO

2009 ◽  
Vol 113 (19) ◽  
pp. 8460-8464 ◽  
Author(s):  
Luyan Li ◽  
Weihua Wang ◽  
Hui Liu ◽  
Xindian Liu ◽  
Qinggong Song ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
First Principles ◽  
Electronic Band Structure ◽  
First Principles Calculations ◽  
Electronic Band ◽  
Doped Zno

Electronic and optical properties of pentagonal-B2C monolayer: A first-principles calculation

2017 ◽  
Vol 31 (08) ◽  
pp. 1750044 ◽  
Author(s):  
Mosayeb Naseri ◽  
Jafar Jalilian ◽  
A. H. Reshak
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Valence Band Maximum ◽  
First Principles Calculation ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Energy Consideration ◽  
Normal Light

The electronic and optical properties of pentagonal B2C (penta-B2C) monolayer are investigated by means of the first-principles calculations in the framework of the density functional theory. The cohesive energy consideration confirms the good stability of the B2C nanostructure in this phase. The electronic band structure reveals that the valence band maximum (VBM) is located at [Formula: see text]-point of the first Brillouin zone (BZ) whereas the conduction band minimum (CBM) is situated at the center of the BZ, resulting in an indirect energy bandgap of about 1.5 eV. Furthermore, a calculated low absorption and low reflection of the material in low energy ranges denote the transparency of the B2C monolayer in the investigated range for normal light incidence. The obtained results may find application in fabrication of future opto-electronic devices.

scholarly journals Electronic Structure and Optical Properties of ZnGeN2

1999 ◽  
Vol 4 (S1) ◽  
pp. 600-605 ◽  
Author(s):  
Sukit Limpijumnong ◽  
Sergey N. Rashkeev ◽  
Walter R. L. Lambrecht
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Nonlinear Optical ◽  
Electronic Band Structure ◽  
Nonlinear Optical Material ◽  
Absorption Data ◽  
Electronic Band ◽  
Linear And Nonlinear ◽  
Ternary Nitride ◽  
Good Agreement

The electronic band structure, structural and bonding, and some linear and nonlinear optical properties are calculated for a new ternary nitride compound ZnGeN2 using first-principles methods. Good agreement is obtained with crystallographic data and with absorption data on the band gap. The prospects for use as nonlinear optical material are discussed.

scholarly journals Ni-rich Nitrides ANNi3 (A = Pt, Ag, Pd) in Comparison with Superconducting ZnNNi3

2011 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
M. A. Ali ◽  
A. K. M. A. Islam ◽  
M. S. Ali
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Generalized Gradient ◽  
Band Structures ◽  
Electronic Band ◽  
Metallic Behavior ◽  
Reflectivity Spectra ◽  
Densities Of States ◽  
Parameter Values

This article reports on the elastic, electronic and optical properties of predicted Ni-rich nitrides ANNi3 (A= Pt, Ag, Pd) in comparison with isostructural superconducting counterpart ZnNNi3. We have used first-principles density functional theory (DFT) with generalized gradient approximation (GGA). The independent elastic constants (C11, C12, and C44), bulk modulus B, compressibility K, shear modulus G, and Poisson’s ratio υ, as well as the band structures, total and partial densities of states and finally the optical properties of ANNi3 have been calculated. The results are then analyzed and compared with those of the superconducting ZnNNi3. The electronic band structures of the three compounds show metallic behavior with a high density of states at the Fermi level in which Ni 3d states dominate just like the superconducting ZnNNi3. Analysis of Tc expression using available  parameter values suggests that the three compounds are less likely to be superconductors. Optical reflectivity spectra indicate that all the compounds have the potential to be used as a coating to remove solar heating.Keywords: ANNi3; Ab initio calculations; Elastic properties; Electronic band structure; Optical properties.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i1.9026J. Sci. Res. 4 (1), 1-10 (2012)

Electronic Structure and Optical Properties of ZnGeN2

1998 ◽  
Vol 537 ◽  
Author(s):  
Sukit Limpijumnong ◽  
Sergey N. Rashkeev ◽  
Walter R. L. Lambrecht
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Nonlinear Optical ◽  
Electronic Band Structure ◽  
Nonlinear Optical Material ◽  
Absorption Data ◽  
Electronic Band ◽  
Linear And Nonlinear ◽  
Ternary Nitride ◽  
Good Agreement

AbstractThe electronic band structure, structural and bonding, and some linear and nonlinear optical properties are calculated for a new ternary nitride compound ZnGeN2 using first-principles methods. Good agreement is obtained with crystallographic data and with absorption data on the band gap. The prospects for use as nonlinear optical material are discussed.

Absorption Spectra and Electron-Vibration Coupling of Ti:Sapphire From First Principles

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Hua Bao ◽  
Xiulin Ruan
Keyword(s):  
Optical Properties ◽  
Absorption Spectra ◽  
First Principles ◽  
Electronic Band Structure ◽  
Stokes Shift ◽  
First Principles Calculation ◽  
Band Structure Calculation ◽  
Crystal Field Theory ◽  
Electronic Band ◽  
Vibration Coupling

First-principles calculations are performed to study the absorption spectra and electron-vibration coupling of titanium-doped sapphire (Ti:Al2O3). Geometry optimization shows a local structure relaxation after the doping of Ti. Electronic band structure calculation shows that five additional dopant energy bands are observed around the band gap of Al2O3, and are attributed to the five localized d orbitals of the Ti dopant. The optical absorption spectra are then predicted by averaging the oscillator strength during a 4 ps first-principles molecular dynamics (MD) trajectory, and the spectra agree well with the experimental results. Electron-vibration coupling is further investigated by studying the response of the ground and excited states to the Eg vibrational mode, for which a configuration coordinate diagram is obtained. Stokes shift effect is observed, which confirms the red shift of emission spectra of Ti:sapphire. This work offers a quantitative understanding of the optical properties and crystal-field theory of Ti-doped sapphire. The first-principles calculation framework developed here can also be followed to predict the optical properties and study the electron-vibration coupling in other doped materials.

scholarly journals The structural, elastic, electronic and optical properties of MgCu under pressure: A first-principles study

2016 ◽  
Vol 30 (27) ◽  
pp. 1650199 ◽  
Author(s):  
Md. Afjalur Rahman ◽  
Md. Zahidur Rahaman ◽  
Md. Atikur Rahman
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Structural Parameters ◽  
Normal Pressure ◽  
Type Structure ◽  
Ultraviolet Region ◽  
Electronic Band ◽  
Electronic And Optical Properties

The effect of pressure on the structural, elastic and electronic properties of the intermetallic compound MgCu with a CsCl-type structure have been investigated using ab initio technique. The optical properties have been studied under normal pressure. We have carried out the plane-wave pseudopotential approach within the framework of the first-principles density functional theory (DFT) implemented within the CASTEP code. The calculated structural parameters show a good agreement with the experimental and other theoretical results. The most important elastic properties including the bulk modulus [Formula: see text], shear modulus [Formula: see text], Young’s modulus [Formula: see text] and Poisson’s ratio [Formula: see text] of the cubic-type structure MgCu are determined under pressure by using the Voigt–Reuss–Hill (VRH) averaging scheme. The results show that the MgCu intermetallic becomes unstable under pressure more than 15 GPa. The study of Cauchy pressure and Pugh’s ratio exhibit brittle nature of MgCu at ambient condition and the compound is transformed into ductile nature with the increase of pressure. For the first time we have investigated the electronic and optical properties of MgCu. The electronic band structure reveals metallic conductivity and the major contribution comes from Cu-[Formula: see text] states. Reflectivity spectrum shows that the reflectivity is high in the ultraviolet region up to 72 eV.

Ab initio calculation on the Optical Properties of AA- Stacked two dimensional Graphene, Silicene, Germanene, and Stanene

2018 ◽  
Vol 1 (1) ◽  
pp. 46-50
Author(s):  
Rita John ◽  
Benita Merlin
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Complex Refractive Index ◽  
Single Layer ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Wide Range ◽  
Optical Region

In this study, we have analyzed the electronic band structure and optical properties of AA-stacked bilayer graphene and its 2D analogues and compared the results with single layers. The calculations have been done using Density Functional Theory with Generalized Gradient Approximation as exchange correlation potential as in CASTEP. The study on electronic band structure shows the splitting of valence and conduction bands. A band gap of 0.342eV in graphene and an infinitesimally small gap in other 2D materials are generated. Similar to a single layer, AA-stacked bilayer materials also exhibit excellent optical properties throughout the optical region from infrared to ultraviolet. Optical properties are studied along both parallel (||) and perpendicular ( ) polarization directions. The complex dielectric function (ε) and the complex refractive index (N) are calculated. The calculated values of ε and N enable us to analyze optical absorption, reflectivity, conductivity, and the electron loss function. Inferences from the study of optical properties are presented. In general the optical properties are found to be enhanced compared to its corresponding single layer. The further study brings out greater inferences towards their direct application in the optical industry through a wide range of the optical spectrum.

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