First-principle calculation of the electronic structure, DOS and effective mass TlInSe2

2017 ◽  
Vol 31 (14) ◽  
pp. 1750155 ◽  
Author(s):  
N. A. Ismayilova ◽  
G. S. Orudzhev ◽  
S. H. Jabarov
Keyword(s):  
Electronic Structure ◽  
Effective Mass ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
Effective Masses ◽  
Structure Density

The electronic structure, density of states (DOS), effective mass are calculated for tetragonal TlInSe2 from first principle in the framework of density functional theory (DFT). The electronic structure of TlInSe2 has been investigated by Quantum Wise within GGA. The calculated band structure by Hartwigsen–Goedecker–Hutter (HGH) pseudopotentials (psp) shows both the valence band maximum and conduction band minimum located at the T point of the Brillouin zone. Valence band maximum at the T point and the surrounding parts originate mainly from 6s states of univalent Tl ions. Bottom of the conduction band is due to the contribution of 6p-states of Tl and 5s-states of In atoms. Calculated DOS effective mass for holes and electrons are [Formula: see text], [Formula: see text], respectively. Electron effective masses are fairly isotropic, while the hole effective masses show strong anisotropy. The calculated electronic structure, density of states and DOS effective masses of TlInSe2 are in good agreement with existing theoretical and experimental results.

Structural and Electronic Structure of SnO2 by the First-Principle Study

2012 ◽  
Vol 725 ◽  
pp. 265-268 ◽  
Author(s):  
Minoru Oshima ◽  
Kenji Yoshino
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Valence Band ◽  
Conduction Band ◽  
Valence Band Maximum ◽  
First Principle ◽  
Band Maximum ◽  
First Principle Calculations ◽  
Calculation Results ◽  
Good Agreement

We performed first-principle calculations to investigate the effects of F, Cl and Sb impurities on the electronic properties of SnO2. We obtained, firstly, the electronic structure of SnO2, a valence band maximum of SnO2is an O 2p orbital and a conduction band minimum was an antibonding Sn 5s and O 2p orbitals dominantly. Secondly, those impurites doped SnO2was obtained the electronic structure. The F, Cl and Sb impurities as n-type dopants exhibited shallow donors. This calculation results were in good agreement with our prvious experiment that we obtained the low resistivity SnO2.

scholarly journals Ab initioStudies of Electronic Structure of Defects in PbTe

2005 ◽  
Vol 864 ◽  
Author(s):  
Salameh Ahmad ◽  
Daniel Bilc ◽  
S.D. Mahanti ◽  
M.G. Kanatzidis
Keyword(s):  
Electronic Structure ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
Resonance State ◽  
Interesting Case ◽  
The Other ◽  
Defect States ◽  
Strong Resonance ◽  
Structure Calculations

AbstractAb initioelectronics structure calculations have been carried out in a series of RPb2n-1Te2n, n=16, compounds to understand the nature of “defect” states introduced by R where R = vacancy, monovalent Na, K, Rb, Cs, Ag atoms and divalent Cd atoms. We find that the density of states (DOS) near the top of the valence band and the bottom of the conduction band get significantly modified. The Na atom seems to perturb this region least (ideal acceptor in PbTe) and the other monovalent atoms enhance the DOS near the top of the valence band. Cd is an interesting case, since it introduces a strong resonance state near the bottom of the conduction band.

scholarly journals (112) Surface of CuInSe2Thin Films with Doped Cd Atoms

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Bo Yin ◽  
Chaogang Lou
Keyword(s):  
Thin Films ◽  
Electronic Structure ◽  
Valence Band ◽  
Electronic Structures ◽  
Formation Energy ◽  
Valence Band Maximum ◽  
Band Maximum ◽  
Doping Behavior

The doping behavior of Cd atoms in the CuInSe2thin films and their influences on electronic structures are investigated. The doped Cd atoms replace Cu atoms and prefer to stay at the (112) surface of the thin films. They combine with Cu vacancies to form defect pairs due to low formation energy. The Cd atom does not by itself modify significantly the electronic structure of the surface, but the defect pairs have important influences. They result in a down shift of valence band maximum and form a hole barrier at the surface, which can prevent holes from reaching the surface and reduce the recombination of carriers.

First-Principles Calculations on the Electronic Structure of ZnO Nanowires

2012 ◽  
Vol 198-199 ◽  
pp. 23-27
Author(s):  
Nan Zhang ◽  
Hong Sheng Zhao ◽  
Dong Yang ◽  
Wen Jie Yan
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
Density Functional ◽  
Valence Band Maximum ◽  
Zno Nanowires ◽  
Cross Sectional ◽  
Quantum Size

Based upon the density functional theory (DFT) in this paper, the first-principles approach is used to study the electronic structure of different cross-sectional diameters of ZnO [0001] nanowires of wurtzite structure. The results show that ZnO [0001] nanowires have a wide direct band gap. Located in the G-point of the Brillouin zone the conduction band minimum and valence band maximum are relatively smooth. The conduction band is mainly composed of Zn 4s and Zn 4p states, and the valence band is composed of Zn 3d and O 2p states. The effective mass of conduction band electrons and valence band holes are large while their mobility is very low which show that conductive ability of pure defect-free [0001] ZnO nanowires is weak. Along with the increase of the cross-sectional diameters, the band gap gradually decreases that indicates quantum size effects are obvious in the nano size range.

scholarly journals First-principle calculations of effective mass of silicon crystal with vacancy defects

2016 ◽  
Vol 34 (4) ◽  
pp. 916-923 ◽  
Author(s):  
Shuying Zhong ◽  
Musheng Wu ◽  
Xueling Lei
Keyword(s):  
Valence Band ◽  
Crystalline Silicon ◽  
Valence Band Maximum ◽  
Energy Bands ◽  
Electron Hole ◽  
Vacancy Defects ◽  
Band Maximum ◽  
Effective Masses ◽  
Jahn Teller ◽  
Gap States

AbstractThe energy band structures and electron (hole) effective masses of perfect crystalline silicon and silicon with various vacancy defects are investigated by using the plane-wave pseudopotential method based on density functional theory. Our results show that the effect of monovacancy and divacancy on the energy band structure of crystalline silicon is primarily reflected in producing the gap states and the local states in valence band maximum. It also causes breaking the symmetry of energy bands resulting from the Jahn-Teller effect, while only producing the gap states for the crystalline silicon with hexavacancy ring. However, vacancy point defects could not essentially affect the effective masses that are derived from the native energy bands of crystalline silicon, except for the production of defect states. Simultaneously, the Jahn-Teller distortions only affect the gap states and the local states in valence band maximum, but do not change the symmetry of conduction band minimum and the nonlocal states in valence band maximum, thus the symmetry of the effective masses. In addition, we study the electron (hole) effective masses for the gap states and the local states in valence band maximum.

scholarly journals CALCULATION OF ELECTRONIC STRUCTURE OF 2D NaAu INTERMETALLIC LAYERS

2021 ◽  
pp. 475-482
Author(s):  
Юрий Александрович Кузнецов ◽  
Михаил Николаевич Лапушкин
Keyword(s):  
Electronic Structure ◽  
Intermetallic Compound ◽  
Band Gap ◽  
Valence Band ◽  
Conduction Band ◽  
Density Of States ◽  
Intermetallic Layers

Проведен расчет плотности состояний различной толщины 2D -слоев интерметаллида NaAu. 2D -слоев интерметаллида NaAu моделировались суперячейки NaAu (111) 2 х 2 х 2. Для монослойного 2D -слоя интерметаллида NaAu установлено наличие запрещенной зоны с шириной 1,87 эВ. Увеличение толщины толщины 2D -слоев интерметаллида NaAu до двух монослоев показал уменьшение ширины запрещенной зоны до 0,81эВ. Дальнейшее увеличение толщины 2D -слоев интерметаллида NaAu приводит к исчезновению запрещенной зоны, что указывает на переход полупроводник - металл для 2D -слоя интерметаллида NaAu толщиной три монослоя. Валентная зона 2D -слоя интерметаллида NaAu сформирована в основном Au 5d электронами, с незначительным вкладом Au 6s и Au 6p электронов. Зона проводимости NaAu образована в основном Au 6р электронами с незначительным вкладом электронов Na 3 s . The calculation of the density of states of various thicknesses of the 2D -layers of the intermetallic compound has been carried out. 2D -layers of intermetallic compound NaAu are simulated by supercells NaAu (111) 2 x 2 x 2. For a monolayer 2D -layer of an intermetallic compound NaAu the presence of a bandgap with a width of 1,87 eV has been established. An increase in the thickness of the 2D -layers of the intermetallic compound NaAu to two monolayers showed a decrease in the bandgap to 0,81 eV. A further increase in the thickness of the 2D -layers of the intermetallic compound NaAu leads to the disappearance of the band gap, which indicates a semiconductor-metal transition for the 2D -layer of the intermetallic compound NaAu with a thickness of three monolayers. The valence band of the 2D -layer of the intermetallic compound NaAu is formed mainly by Au 5d electrons, with an insignificant contribution from Au 6s and Au 6p electrons. The conduction band of NaAu is formed mainly by Au 6p electrons with an insignificant contribution of electrons Na 3s .

Co-doping of magnesium with indium in nitrides: first principle calculation and experiment

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 5111-5115 ◽  
Author(s):  
Zhiqiang Liu ◽  
Binglei Fu ◽  
Xiaoyan Yi ◽  
Guodong Yuan ◽  
Junxi Wang ◽  
...  
Keyword(s):  
Valence Band ◽  
Valence Band Maximum ◽  
First Principle ◽  
Principle Calculation ◽  
First Principle Calculation ◽  
Band Maximum ◽  
Co Doping ◽  
P Type

The valence band maximum could be modified by specific states coupling, thus improving the p-type dopability in In–Mg co-doping GaN.

Antimony as A Passivant of Si(111) in the Si(111) (√3×√3)-Sb System

1992 ◽  
Vol 259 ◽  
Author(s):  
A. Hughes ◽  
T-H. Shen ◽  
C.C. Matthai
Keyword(s):  
Fermi Level ◽  
Valence Band ◽  
Density Of States ◽  
Surface State ◽  
Tight Binding ◽  
Valence Band Maximum ◽  
Electronic Density ◽  
Band Maximum ◽  
Electronic Density Of States ◽  
Tight Binding Method

ABSTRACTThe electronic density of states (DOS) for the Si(111) (√3×√3)-Sb system has been calculated using the tight binding method in the Extended Hiickel Approximation. We find that there is a gap of about 0.8eV between the valence band maximum (VBM) and a surface state. This is in contrast with the case of the unreconstructed (lxl) surface where the Fermi level lies at the surface state.

Sign in / Sign up

Export Citation Format

Share Document