Optical Absorption of Large Band-Gap SbxBi1-xI3 Alloys

2002 ◽  
Vol 744 ◽  
Author(s):  
C. Persson ◽  
R. Ahuja ◽  
J. Souza de Almeida ◽  
B. Johansson ◽  
C. Y. An ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Band Gap Energy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Calculated Density ◽  
Augmented Plane Wave ◽  
Gap Energy ◽  
Generalized Gradient Approximation ◽  
Absorption Measurements

ABSTRACTThe optical properties of SbBiI3 alloys have been investigated experimentally by absorption measurements and theoretically by a full-potential augmented plane wave (FPLAPW) method within the generalized gradient approximation. The fundamental band-gap energy of these alloys changes from BiI3- to SbI3-like with increasing percentage of Sb content. The calculated band-gap energies as well as the optical absorption were found to be in a very good qualitatively agreement with the experimental results. We present calculated density-of-states as well as the dielectric functions for evaluation of future experiments.

scholarly journals Computational Investigation of the Folded and Unfolded Band Structure and Structural and Optical Properties of CsPb(I1−xBrx)3 Perovskites

Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 342 ◽  
Author(s):  
Hamid M. Ghaithan ◽  
Zeyad A. Alahmed ◽  
Andreas Lyras ◽  
Saif M. H. Qaid ◽  
Abdullah S. Aldwayyan
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Band Gap ◽  
Spectral Weight ◽  
Band Gap Energy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Electronic And Optical Properties ◽  
Generalized Gradient Approximation ◽  
Direct Band

The structural, electronic, and optical properties of inorganic CsPb(I1−xBrx)3 compounds were investigated using the full-potential linear augmented-plane wave (FP-LAPW) scheme with a generalized gradient approximation (GGA). Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and modified Becke–Johnson GGA (mBJ-GGA) potentials were used to study the electronic and optical properties. The band gaps calculated using the mBJ-GGA method gave the best agreement with experimentally reported values. CsPb(I1−xBrx)3 compounds were wide and direct band gap semiconductors, with a band gap located at the M point. The spectral weight (SW) approach was used to unfold the band structure. By substituting iodide with bromide, an increase in the band gap energy (Eg) values of 0.30 and 0.55 eV, using PBE-GGA and mBJ-GGA potentials, respectively, was observed, whereas the optical property parameters, which were also investigated, demonstrated the reverse effect. The high absorption spectra in the ultraviolet−visible energy range demonstrated that CsPb(I1−xBrx)3 perovskite could be used in optical and optoelectronic devices by partly replacing iodide with bromide.

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.

scholarly journals Optical absorption of divalent metal tungstates: Correlation between the band-gap energy and the cation ionic radius

2008 ◽  
Vol 83 (3) ◽  
pp. 37002 ◽  
Author(s):  
R. Lacomba-Perales ◽  
J. Ruiz-Fuertes ◽  
D. Errandonea ◽  
D. Martínez-García ◽  
A. Segura
Keyword(s):  
Optical Absorption ◽  
Band Gap ◽  
Ionic Radius ◽  
Band Gap Energy ◽  
Divalent Metal ◽  
Gap Energy ◽  
Metal Tungstates

First Principle Study on Electronic Structure of Nanocrystalline BaTiO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 2510-2512
Author(s):  
Xiang Yun Deng ◽  
Long Tu Li ◽  
Xiao Hui Wang ◽  
Zhi Lun Gui
Keyword(s):  
Electronic Structure ◽  
Partial Density ◽  
Full Potential ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Augmented Plane Wave Method ◽  
Nanocrystalline Batio3 Ceramics ◽  
Linearized Augmented Plane Wave

The full potential linearized augmented plane wave method within the generalized gradient approximation was used to calculate electronic structure of nanocrystalline BaTiO3 ceramics. We calculated the total and partial density of states of 50 nm BaTiO3 ceramics. The results show that the atoms distribution of nanograin BaTiO3 ceramics is different from those of coarse BaTiO3 ceramics. It is also revealed that the hybridization between Ti 3d and O 2p is very strong, which is very important to the ferroelectric stability of nanocrystalline BaTiO3 ceramics.

SEGREGATION OF Cu IN THE Cu/Ni MULTILAYERS

2008 ◽  
Vol 22 (20) ◽  
pp. 1893-1902
Author(s):  
L. Y. LI ◽  
G. H. YU ◽  
F. W. ZHU
Keyword(s):  
Approximation Formula ◽  
Full Potential ◽  
Slab Surface ◽  
Generalized Gradient ◽  
Augmented Plane Wave ◽  
Plane Wave Method ◽  
Generalized Gradient Approximation ◽  
Augmented Plane Wave Method ◽  
Linearized Augmented Plane Wave ◽  
Vacuum Effect

The segregation of Cu atoms in the Cu/Ni multilayers was investigated by means of the full-potential linearized augmented plane-wave method with the generalized-gradient approximation formula. We investigated the segregation of Cu atoms when the Cu/Ni slab is along the (001) and (111) directions, respectively. The results obtained show that at most one-layer Cu atoms can segregate to the Ni surface when Ni films are deposited on the Cu substrate and the segregation of Cu atoms is not sensitive to the orientation of the Cu/Ni slab surface. The result of Cu segregation is to reduce the vacuum effect.

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 Tl2S–In2S3–GeS2 Glass System as Novel Promising Materials for Photonics

2019 ◽  
Vol 20 (4) ◽  
pp. 416-422
Author(s):  
O.V. Tsisar ◽  
L.V. Piskach ◽  
O.V. Parasyuk ◽  
O.V. Zamurujeva ◽  
G.L. Myronchuk ◽  
...  
Keyword(s):  
Glass Transition ◽  
Optical Absorption ◽  
Band Gap ◽  
Structural Properties ◽  
Band Gap Energy ◽  
Optical Absorption Spectra ◽  
Characteristic Energy ◽  
Gap Energy ◽  
Glass Forming ◽  
Melting Temperatures

It was established that minimal content of the glass-forming component GeS2 is equal to 30 mol.% (by exploration the set of 23 different alloys with different composition). Correlation between structural properties, thermal parameters (glass transition, crystallization and melting temperatures) and optical absorption spectra along of the titled glasses system has been found. The temperatures, the band gap energy and the characteristic energy of vitreous alloys for the gastric system Tl2S‑In2S3‑GeS2 were investigated experimentally.

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.

Mn-Disorder Effect on Magnetism and Half Metallicity of NiCoMnGa Quaternary Heusler Alloy

2012 ◽  
Vol 585 ◽  
pp. 270-273 ◽  
Author(s):  
Mukhtiyar Singh ◽  
Hardev S. Saini ◽  
Manish K. Kashyap
Keyword(s):  
Heusler Alloy ◽  
Full Potential ◽  
Generalized Gradient ◽  
Half Metallicity ◽  
Augmented Plane Wave ◽  
Generalized Gradient Approximation ◽  
Disorder Effect ◽  
Linearized Augmented Plane Wave ◽  
Mn Concentration ◽  
Disordered Alloy

The full potential linearized augmented plane wave (FPLAPW) method within generalized gradient approximation (GGA) has been used to investigate the effect of disorder between Ni and Mn atoms on the electronic and magnetic properties of NiCoMnGa quaternary Heusler alloy. We observed that the increase in Mn concentration in NiCoMnGa destroys the half metallicity and decreases the total magnetic moment. Further, the disordered alloy exists in ferrimagnetic (FiM) ground state rather than ferromagnetic (FM) one of ordered system due to antiparallel alignment of extra Mn atom with respect to original Mn atom.

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