Optical Properties of Si Quantum Dot Potential under Pressure Effect

2012 ◽  
Vol 545 ◽  
pp. 32-37
Author(s):  
Y. Al-Douri
Keyword(s):  
Optical Properties ◽  
Quantum Dot ◽  
Energy Gap ◽  
Pressure Effect ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Si Quantum Dot ◽  
Linearized Augmented Plane Wave ◽  
Transverse Effective Charge

Further study of the quantum dot potential under hydrostatic pressure for Si is presented. This potential has been calculated by means of our recent empirical model. The indirect energy gap (Γ-X) is calculated using the full potential-linearized augmented plane wave (FP-LAPW) method. The Engel-Vosko generalized gradient approximation (EV-GGA) formalism is used to optimize the corresponding potential for energetic transition and optical properties calculations of Si. The refractive index and transverse effective charge are predicted under pressure effect. The pressure effect is used to test the validity of our model. The results are compared with others and showed reasonable agreement.

Band Structure and Optical Properties of CuInSe2

2014 ◽  
Vol 894 ◽  
pp. 254-258
Author(s):  
Rong Zhen Chen ◽  
Clas Persson
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Coupling Effect ◽  
Full Potential ◽  
Spin Orbit Coupling ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

In this work, the electronic structure and dielectric function of chalcopyrite CuInSe2 are presented. The results are based on the full-potential linearized augmented plane wave (FPLAPW) method using the generalized gradient approximation (GGA) plus an onsite Coulomb interaction U of the Cu d states. The dielectric constant, absorption coefficient and refractive index are explored by means of optical response. The spin-orbit coupling effect is considered for the calculations of electronic structure and optical properties. We find that the results based on our calculation method have good agreement compared with experimental and other earlier simulations results.

scholarly journals The study of structural, elastic, electronic and optical properties of CsYx I(1 − x)(Y = F, Cl, Br) using density functional theory

2017 ◽  
Vol 35 (1) ◽  
pp. 197-210 ◽  
Author(s):  
Shabeer Ahmad Mian ◽  
Muhammad Muzammil ◽  
Gul Rahman ◽  
Ejaz Ahmed
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
G Ratio ◽  
Linearized Augmented Plane Wave ◽  
Incremental Addition

AbstractThe structural, electronic, elastic and optical properties of CsYx I(1 − x)(Y = F, Cl, Br) are investigated using full potential linearized augmented plane wave (FP-LAPW) method within the generalized gradient approximation (GGA). The ground state properties such as lattice constant (ao) and bulk modulus (K) have been calculated. The mechanical properties including Poisson’s ratio (σ), Young’s modulus (E), anisotropy factor (A) and shear modulus (G) were also calculated. The results of these calculations are comparable with the reported experimental and theoretical values. The ductility of CsYx I(1 − x) was analyzed using Pugh’s rule (B/G ratio) and Cauchy’s pressure (C12−C44). Our results revealed that CsF is the most ductile among the CsYxI(1 − x)(Y = F, Cl, Br) compounds. The incremental addition of lighter halogens (Yx) slightly weakens the strength of ionic bond in CsYxI(1 − x). Moreover, the optical transitions were found to be direct for binary and ternary CsYxI(1 − x). We hope that this study will be helpful in designing binary and ternary Cs halides for optoelectronic applications.

Ab initio investigation of the structural, electronic, magnetic and optical properties of the perovskite TlMnX3 (X = F, Cl) compounds

2016 ◽  
Vol 30 (07) ◽  
pp. 1650031 ◽  
Author(s):  
Farida Hamioud ◽  
Ghadah S. AlGhamdi ◽  
Saleh Al-Omari ◽  
A. A. Mubarak
Keyword(s):  
Ab Initio ◽  
Energy Gap ◽  
Optical Spectra ◽  
Index Formula ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Semiconductor Behavior ◽  
Technology Applications ◽  
Linearized Augmented Plane Wave

We have performed ab initio investigation of some physical properties of the perovskite TlMnX3 (X = F, Cl) compounds using the full-potential linearized augmented plane wave (FP-LAPW) method. The generalized gradient approximation (GGA) is employed as exchange-correlation potential. The calculated lattice constant and bulk modulus agree with previous studies. Both compounds are found to be elastically stable. TlMnF3 and TlMnCl3 are classified as anisotropic and ductile compounds. The calculations of the band structure of the studied compounds showed the semiconductor behavior with the indirect (M–X) energy gap. Both compounds are classified as a ferromagnetic due to the integer value of the total magnetic moment of the compounds. The different optical spectra are calculated from the real and the imaginary parts of the dielectric function and connected to the electronic structure of the compounds. The static refractive index [Formula: see text] is inversely proportional to the energy bandgap of the two compounds. Beneficial optics technology applications are predicted based on the optical spectra.

First-principles calculations for optical investigations of PbX (X = S, Te) compounds under quantum dots diameter effect

2015 ◽  
Vol 93 (12) ◽  
pp. 1490-1494 ◽  
Author(s):  
Y. Al-Douri ◽  
H. Khachai ◽  
R. Khenata ◽  
A. Bouhemadou
Keyword(s):  
Quantum Dot ◽  
Density Functional ◽  
Energy Gap ◽  
Theoretical Data ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Optical Dielectric Constant ◽  
Optical Dielectric ◽  
Linearized Augmented Plane Wave

The full potential-linearized augmented plane wave (FP-LAPW) method is implemented in WIEN2K code to calculate the indirect energy gap (Γ–X) using density functional theory. The Engel–Vosko generalized gradient approximation (EVGGA) and modified Becke–Johnson (mBJ) formalisms are used to optimize the corresponding potential for energetic transition and optical properties calculations of PbS and PbTe compounds as a function of quantum dot diameter and are used to test the validity of our model of quantum dot potential. The refractive index and optical dielectric constant are investigated to explore best applications for solar cells. The calculated results are in agreement with other experimental and theoretical data.

scholarly journals First-principles calculations of antimony sulphide Sb2S3

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Afiq Radzwan ◽  
Rashid Ahmed ◽  
Amiruddin Shaari ◽  
Abdullahi Lawal ◽  
Ying Xuan Ng
Keyword(s):  
Optical Properties ◽  
Electronic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Metal Chalcogenides ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Linearized Augmented Plane Wave

The structural, electronic and optical  properties of Sb2S3 have been investigated  using full-potential linearized augmented plane wave method within density functional theory (DFT) framework, treating exchange-correlation potential with Engel-Vosko generalized gradient approximation (EV-GGA). Electronic properties calculations were performed  with and without taken into account the effects of spin-orbit coupling (SOC) . From our results we found that structural properties,density of states and band structure are in good agreement with experimental results.The effects of SOC and relativistic on electronic properties were found to be negligible. However, optical properties, namely, imaginary and real parts of dielectric function, reflectivity, absorption coefficient, refractive index, extinction coefficient and energy loss function were calculated and analyized.Optical gap of 1.61 eV proves that Sb2S3 metal chalcogenides is a promising material for solar cell device.

scholarly journals Structural, electronic, optical properties and first-principles calculations of Sr1-xCaxWO4 ceramics

2019 ◽  
Vol 9 (3) ◽  
pp. 199-211
Author(s):  
Mohammed Ait Haddouch ◽  
Youssef Tamraoui ◽  
Fatima-Ezzahra Mirinioui ◽  
Youssef Aharbil ◽  
Hicham Labrim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Solid State Reaction Method ◽  
Full Potential ◽  
X Ray Diffraction ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Linearized Augmented Plane Wave

A series of strontium calcium tungstates Sr1-xCaxWO4 powders with (x = 0; 0.25; 0.5; 0.75 and 1.0) were prepared by solid-state reaction method and analyzed by X-ray diffraction (XRD). All these compositions possess a tetragonal scheelite structure with I41/a space group. Raman active vibrational modes in the range from 20 to 1000 cm-1 of the series Sr1-xCaxWO4 with tetragonal structure exhibit 13 modes in arrangement with the Group theory analysis of structural Raman-active modes. The optical properties were investigated using the diffuse reflectance UV–visible absorbance spectrum. Based on Density Functional Theory (DFT) and using full Potential-linearized Augmented Plane Wave (FP-LAPW) method with the Local Density Approximation and the Generalized Gradient Approximation (GGA), implemented in the Wien2k package, we have investigated electronic and optical properties of all the compositions. The results indicate a decrease in the values of the optical direct bandgap (from 4.29 to 3.87 eV) with the increase of Ca into SrWO4 lattice, which is in good agreement with our experimental results.

FIRST PRINCIPLES STUDY OF STRUCTURAL, ELECTRONIC AND OPTICAL PROPERTIES OF HALF-HEUSLER ALLOYS LIMGN, NaMGN AND KMGN

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Nor Safikah Masuri ◽  
R. Ahmed ◽  
A. Shaari ◽  
Bakhtiar Ul Haq ◽  
Mazmira Mohamad ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Structural Parameters ◽  
Heusler Alloys ◽  
Full Potential ◽  
Generalized Gradient ◽  
Previous Theory ◽  
Augmented Plane Wave ◽  
Linearized Augmented Plane Wave ◽  
Good Agreement

In this study, we performed our calculations using the full-potential linearized-augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code based on DFT. The generalized gradient functional with the Wu-Cohen (WC) parameterization was used to evaluate the structural, electronic, optical and thermoelectric properties of the materials under this study. We have calculated the structural parameters and our obtained results are in good agreement with available experimental and previous theory calculations. The density of states and band structure figures have been calculated and analyzed. The optical properties that covered by dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity and energy-loss function have been calculated and analyzed in a range energy from 0eV to 30eV.

scholarly journals The Electronic, Magnetic and Optical Properties of Ba2MUO6  Compounds With (M=Ni, Co, Cd and Zn): DFT Calculation 

2021 ◽  
Author(s):  
Abdelmajid Kadiri ◽  
Mestapha Arejdal ◽  
Abderrahman Abbassi
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Densities Of States ◽  
Electronic Densities ◽  
Experimental Values ◽  
Linearized Augmented Plane Wave

Abstract In this present paper, the electronic, magnetic and optical properties of the double Perovskites Ba2MUO6 with (M=Ni, Co, Cd and Zn) are investigated in the framework of the Generalized Gradient Approximation (GGA), employing the Full Potential-Linearized Augmented Plane Wave (FP-LAPW) method as implemented in the Wien2K package. The only method used to study these three types of the properties of these compounds is Density Functional Theory (DFT) approach. Thanks to this method, several of the detailed results related to the three studied properties of these compounds are determined; specifically, the optimization of parameters of structures, the band structures, the electronic densities of states (DOS), reflectivity, transmittance and absorbance. Finally, the comparison between these results obtained in this theoretical study and the experimental values makes it clear that they are virtually in good agreement with each other.

THE FIRST PRINCIPLE STUDY OF COMPARISON OF DIVALENT AND TRIVALENT IMPURITY IN RRAM DEVICES USING GGA+U

2021 ◽  
pp. 2150039
Author(s):  
EJAZ AHMAD KHERA ◽  
HAFEEZ ULLAH ◽  
MUHAMMAD IMRAN ◽  
HASSAN ALGADI ◽  
FAYYAZ HUSSAIN ◽  
...  
Keyword(s):  
Data Storage ◽  
Random Access ◽  
Resistive Random Access Memory ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Metal Insulator Metal ◽  
Structure Density ◽  
Linearized Augmented Plane Wave

Resistive switching (RS) performances had prodigious attention due to their auspicious potential for data storage. Oxide-based devices with metal insulator metal (MIM) structure are more valuable for RS applications. In this study, we have studied the effect of divalent (nickel) as well as trivalent (aluminum) dopant without and with oxygen vacancy (V[Formula: see text] in hafnia (HfO[Formula: see text]-based resistive random-access memory (RRAM) devices. All calculations are carried out within the full potential linearized augmented plane-wave (FP-LAPW) method based on the WIEN2k code by using generalized gradient approximation (GGA) and generalized gradient approximation with U Hubbard parameters (GGA+U) approach. The studies of the band structure, density of states and charge density reveal that HfNiO2+Vo are more appropriate dopant to enhance the conductivity for RRAM devices.

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