scholarly journals Electron Self-trapping in Ge2 Se3 and its Role in Ag and Sn Incorporation

2012 ◽  
Vol 1431 ◽  
Author(s):  
Arthur H. Edwards ◽  
Kristy A. Campell ◽  
Andrew C. Pineda
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Fermi Level ◽  
Density Functional ◽  
Functional Theory ◽  
Periodic Model ◽  
Self Trapping ◽  
Formation Energies

ABSTRACTWe present a set of density functional theory (DFT) calculations on the electronic structure of Ag and Sn in Ge2 Se3 in a periodic model. We show that electron self-trapping is a persistent feature in the presence of many defects. Ag and Sn autoionize upon entering Ge2 Se3 becoming Ag+ and Sn2+ , respectively, and the freed electrons self trap at the lowest energy site. Both Ag and Sn can substitute for Ge, and we present formation energies as a function of Fermi level that show that Sn can substantially alter the incorporation of Ag into the Ge2Se3 network.

DFT calculations of the synergistic effect of λ-MnO2/graphene composites for electrochemical adsorption of lithium ions

2019 ◽  
Vol 21 (15) ◽  
pp. 8133-8140 ◽  
Author(s):  
Huixin Zhang ◽  
Xiao Du ◽  
Shengqi Ding ◽  
Qiang Wang ◽  
Lutong Chang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Synergistic Effect ◽  
Dft Calculations ◽  
Density Functional ◽  
Lithium Ions ◽  
Functional Theory ◽  
Electrochemical Adsorption

Density functional theory (DFT) was used to calculate the geometric and electronic structure of λ-MnO2 and λ-MnO2/graphene composites.

X-Ray structures, Mössbauer hyperfine parameters, and molecular orbital descriptions of the phthalocyaninato iron(II) azole complexes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 894-903
Author(s):  
Dustin E. Nevonen ◽  
Laura S. Ferch ◽  
Victor Y. Chernii ◽  
David E. Herbert ◽  
Johan van Lierop ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Electronic Structures ◽  
Density Functional ◽  
Reasonable Agreement ◽  
Hyperfine Parameters ◽  
Functional Theory ◽  
X Ray ◽  
X Ray Crystallography

The electronic structures of a set of PcFe(azole)2 complexes (azole = imidazole, [Formula: see text]-methylimidazole, pyrazole, isoxazole, thiazole, 1,2,4-triazole, 3-amino-1,2,4,-triazole, and 5-amino-1,2,3,4-tetrazole) were examined by Mössbauer spectroscopy and Density Functional Theory (DFT) calculations. In addition, the geometric distortions in these compounds were elucidated by X-ray crystallography for imidazole, pyrazole, and thiazole-containing compounds. Predicted by DFT calculations, Mössbauer hyperfine parameters for all compounds are in reasonable agreement with experimental results, and the influence of the [Formula: see text]-donor and [Formula: see text]-acceptor properties of the axial azoles on the electronic structure of the PcFe(azole)2 complexes is demonstrated by comparison with the reference PcFePy2 compound.

scholarly journals Effect of Beryllium and Magnesium Doped Stanene Single Layer on Structural and Electronic Properties Using Density Functional Theory as Implemented in Quantum ESPRESSO

2021 ◽  
Author(s):  
Alhassan Shuaibu ◽  
Yakubu Tanko ◽  
Zainab Abdurrahman ◽  
Abdullahi Lawal ◽  
Maharaz Nasir
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Fermi Level ◽  
Band Gap ◽  
Density Functional ◽  
Energy Gap ◽  
Single Layer ◽  
Quantum Spin ◽  
Band Edge ◽  
Functional Theory

Stanene is a quantum spin hall insulator and a favourable material for electronic and optoelectronic devices. Density functional theory (DFT) calculations are performed to study the band gap opening in stanene by investigating the effect of beryllium and magnesium doped stanene single layer to study the electronic and structural properties in stanene. The electronic band energy of pure stanene without spin orbit coupling (SOC) appear to show no energy gap at the Fermi level showing that stanene is a gapless material with Dirac cones at the K point and the band gap opens by a gap of 0.08 eV is opened at the K point. The electronic structure of Be and Mg doped stanene shows that the Fermi level is shifted towards the valance band edge when compared to pure stanene. We have considered 6.25, 12.5, 18.75 and 25% of both Be and mg doping. The electronic structure of Be doped stanene show that the Fermi level is shifted towards the valance band edge when compared to pure stanene. The Dirac point of stanene locates at Γ shifted by 0.38 and 0.51eV for 6.25 and 12.5 %, an energy band gap of 0.27 and 0.50 eV were obtained above the Fermi level for 6.25 and 12.5% respectively. In the case of Mg, the bandgap remains slightly above the Fermi-level and amounts to 0.34 eV for 6.25 % and 0.43eV for 12.5 %, in the case of 18.75 and 25 % the Dirac cone disappear completely, an energy gap of 0.28 eV and 0.60 eV were obtained above the Fermi level for 6.25 and 12.5% respectively, our findings show that the band gap of stanene open at 12.5% doping concentration of both Be and Mg impurities. These obtained band-gap value seem to be sufficient for use of alkaline earth metal doped stanene in optoelectronic and such applications where stanene is incapacitate for its use to switch on/off devices.

Density Functional Theory and Ab Initio Molecular Dynamics Study of the Effect of Ti and Zr Transition Metals in D03 Fe3Al

2012 ◽  
Vol 706-709 ◽  
pp. 1095-1099
Author(s):  
Sara Chentouf ◽  
Jean Marc Raulot ◽  
Hafid Aourag ◽  
Thierry Grosdidier
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Dft Calculations ◽  
Ab Initio ◽  
Density Functional ◽  
Md Simulations ◽  
Functional Theory ◽  
Ab Initio Md ◽  
Increasing Temperature ◽  
Formation Energies

The formation energies of the T.M impurities Ti and Zr were calculated using DFT calculations at absolute zero and ab initio MD simulations at 300 K. We found that, with increasing temperature, Zr impurities become more stable and prefer to segregate at the interface of ∑5 (310)[001] grain boundary. In the case of Ti, the results show that it remains a stable defect when temperature increases.

scholarly journals Электронные состояния наносистем на основе сульфида кадмия в форме сфалерита

2019 ◽  
Vol 53 (10) ◽  
pp. 1419
Author(s):  
В.Г. Заводинский ◽  
А.П. Кузьменко
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Fermi Level ◽  
Cadmium Sulfide ◽  
Density Functional ◽  
Electronic States ◽  
Functional Theory ◽  
Density Of Electronic States ◽  
The Density Functional Theory ◽  
Semiconductor Properties

The electronic structure of nanosystems on the basis of cadmium sulfide in a blende phase (zb-CdS) is investigated using the method of the density functional theory and pseudo-potentials. It is shown that the used approach allows to describe electronic states of this material rather correctly. It is revealed that the surface (100) - zb-CdS is characterized by the metal-like density of electronic states while the surfaces (110) - zb-CdS has a forbidden band at the Fermi level, and nanofilms with this orientation can be used as material for semiconductor devices. Epitaxial layered nanosystems (110) - zb-CdS-Si also show semiconductor properties.

scholarly journals A study on the synthesis, longitudinal optical phonon–plasmon coupling and electronic structure of Al doped ZnS nanorods

RSC Advances ◽  
2017 ◽  
Vol 7 (20) ◽  
pp. 12382-12390 ◽  
Author(s):  
U. P. Gawai ◽  
U. P. Deshpande ◽  
B. N. Dole
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Dft Calculations ◽  
First Principles ◽  
Density Functional ◽  
Longitudinal Optical ◽  
Plasmon Coupling ◽  
Longitudinal Optical Phonon ◽  
Functional Theory ◽  
Structural And Electronic Properties

First principles density functional theory (DFT) calculations were employed to study the structural and electronic properties of pure and Al doped ZnS nanorods.

Ab Initio Calculations of Electronic Properties of Al Doped LaMnO3 Perovskite Manganites

2015 ◽  
Vol 754-755 ◽  
pp. 762-765
Author(s):  
A. Chik ◽  
S. Saad ◽  
R.M. Zaki ◽  
F. Che Pa ◽  
C.K. Yeoh
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Fermi Level ◽  
Ab Initio ◽  
Electronic Properties ◽  
Density Functional ◽  
Perovskite Manganites ◽  
Functional Theory ◽  
Temperature Range ◽  
Energy Approximation

The electronic structure of the perovskite manganites LaMnO3 and La2/3 Al1/3 MnO3 was presented. The calculations were made within density functional theory (DFT) and PBE exchange correlations energy approximation. It was found that inclusion of Al dopants add additional states near the Fermi level and decreasing the resistivity values for all temperature range.

Research for Photoelectric Property of SnO2 Vacancy Doped Cu

2014 ◽  
Vol 1070-1072 ◽  
pp. 612-615
Author(s):  
Bang Jian Zhang ◽  
Feng Miao
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Fermi Level ◽  
Density Functional ◽  
Photoelectric Property ◽  
Partial Density ◽  
Complex Dielectric Function ◽  
Density Of State ◽  
Functional Theory

Based on Density Functional Theory, we investigated electronic structure and optical properties of Cu vacancy doped SnO2 with density of 4.35%, including the density of state(dos), the partial density of state(PDOS) and complex dielectric function. The results show that Fermi level access valence band with the increase of doped density. And this can attributed to the increased folded state. It has enhanced the electrical and metal property of material.

Experimental and theoretical studies of plasma resonance and the electronic structure of binary skutterudites

2005 ◽  
Vol 886 ◽  
Author(s):  
Øystein Prytz ◽  
Ole M. Løvvik ◽  
Johan Taftø
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Density Functional ◽  
Drude Model ◽  
Theoretical Studies ◽  
Functional Theory ◽  
Potential Applications ◽  
Electron Energy Loss ◽  
Experimental And Theoretical Studies

ABSTRACTWe determine the plasmon energies of the skutterudites CoP3, CoAs3 and CoSb3 by electron energy loss spectroscopy, and compare with calculated values from the Drude model and density functional theory (DFT). For these compounds, whose doped versions have potential applications as thermoelectric materials, there is a relatively large discrepancy between experiment and theory based on the Drude model as well as the DFT-calculations. We also study the transitions from occupied to unoccupied states near the Fermi-level that show up at energies lower than the plasmon energies. The features observed are in general agreement with the DFT-calculations.

Sign in / Sign up

Export Citation Format

Share Document