Effects of thermal disorder on the electronic structure of halide perovskites: insights from MD simulations

2018 ◽  
Vol 20 (40) ◽  
pp. 25693-25700 ◽  
Author(s):  
Marko Mladenović ◽  
Nenad Vukmirović
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Lattice Constant ◽  
Md Simulations ◽  
Thermal Disorder ◽  
Halide Perovskites

The effects of thermal disorder on the electronic properties of organic/inorganic halide perovskites are largest in materials with the smallest lattice constant.

Study on the Effect of Doping on Lattice Constant and Electronic Structure of Bulk AuCu by the Density Functional Theory

2019 ◽  
Vol 11 (02) ◽  
pp. 2030001 ◽  
Author(s):  
Dung Nguyen-Trong ◽  
Cuong Nguyen-Chinh ◽  
Van Duong-Quoc
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Electronic Properties ◽  
Lattice Constant ◽  
Density Of States ◽  
Impurity Concentration ◽  
Density Functional ◽  
Unit Cell ◽  
Functional Theory ◽  
The Density Functional Theory

This paper studies the effect of GGA-PBE, GGA-PBEsol, GGA-PW91, GGA-VWN-BP, LDA-PWC, LDA-VWN parameterized exchange–correlation functionals and Cu impurity concentration on the lattice and electronic properties of bulk AuCu by the Density Functional Theory (DFT). The lattice properties are determined by the lattice constant, the unit cell volume and the total energy on unit cell. The electronic properties are determined by the band gap, the Partial Density of States (PDOS) and the total Density of States (DOS) of materials. The obtained results showed the effect of the interaction potential and the Cu impurity concentration on the lattice structure and the electronic structure of bulk AuCu.

scholarly journals Indirect bandgap, optoelectronic properties, and photoelectrochemical characteristics of high-purity Ta3N5 photoelectrodes

2021 ◽  
Vol 9 (36) ◽  
pp. 20653-20663
Author(s):  
Johanna Eichhorn ◽  
Simon P. Lechner ◽  
Chang-Ming Jiang ◽  
Giulia Folchi Heunecke ◽  
Frans Munnik ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
High Purity ◽  
Optoelectronic Properties ◽  
Precise Control ◽  
Insight Into

The (opto)electronic properties of Ta3N5 photoelectrodes are often dominated by defects, but precise control of these defects provides new insight into the electronic structure, photocarrier transport, and photoelectrochemical function.

Molecular Dynamics Study Of Si/Si3N4 Interface

1996 ◽  
Vol 446 ◽  
Author(s):  
Martina E. Bachlechner ◽  
Ingvar Ebbsjö ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Molecular Dynamics ◽  
Electronic Structure ◽  
Charge Transfer ◽  
Md Simulations ◽  
Electronic Structure Calculations ◽  
Interface Structure ◽  
Bond Bending ◽  
Three Body ◽  
Structure Calculations ◽  
Weber Potential

AbstractStructural correlations at the Si(111)/Si3N4(0001) interface are studied using the molecular dynamics (MD) method. In the bulk, Si is described by the Stillinger-Weber potential and Si3N4 by an interaction potential which contains two-body (steric, Coulomb, electronic polarizabilities) and three-body (bond bending and stretching) terms. At the interface, the charge transfer from silicon to nitrogen is taken from LCAO electronic structure calculations. Using these Si, Si3N4 and interface interactions in MD simulations, the interface structure (atomic positions, bond lengths, and bond angles) is determined. Results for fracture in silicon are also presented.

Theory Of 3d Transition Metal Defects In 3C SiC

1996 ◽  
Vol 442 ◽  
Author(s):  
Harald Overhof
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Electronic Properties ◽  
Crystal Field ◽  
High Spin ◽  
Crystal Field Splitting ◽  
Large Crystal ◽  
Field Splitting ◽  
Vacancy Model ◽  
The Difference

AbstractThe electronic properties of 3d transition metal (TM) defects located on one of the four different tetrahedral positions in 3C SiC are shown to be quite site-dependent. We explain the differences for the 3d TMs on the two substitutional sites within the vacancy model: the difference of the electronic structure between the carbon vacancy VC and the silicon vacancy VSi is responsible for the differences of the 3d TMs. The electronic properties of 3d TMs on the two tetrahedral interstitial sites differ even more: the TMs surrounded tetrahedrally by four Si atoms experience a large crystal field splitting while the tetrahedral C environment does not give rise to a significant crystal field splitting at all. It is only in the latter case that high-spin configurations are predicted.

A multi-technique comparison of the electronic properties of pristine and nitrogen-doped polycrystalline SnO2

2016 ◽  
Vol 18 (32) ◽  
pp. 22617-22627 ◽  
Author(s):  
S. Livraghi ◽  
N. Barbero ◽  
S. Agnoli ◽  
C. Barolo ◽  
G. Granozzi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Spectroscopic Techniques ◽  
Nitrogen Doped ◽  
Technique Comparison

The electronic structure of nitrogen doped tin(iv) oxide (SnO2) materials prepared in the form of nanometric powders has been characterized employing a variety of spectroscopic techniques.

DFT Investigation of Substitution Effects on the Electronic Properties of Perylene Bisimides Derivatives

2014 ◽  
Vol 513-517 ◽  
pp. 347-350
Author(s):  
Bo Wei Chen ◽  
Ye Wei Xu ◽  
Lin Zhang
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Absorption Spectra ◽  
Electronic Structures ◽  
Semiconductor Materials ◽  
Substitution Effects ◽  
Density Functions ◽  
Computational Results ◽  
Good Accordance ◽  
Perylene Bisimides

Perylene Bisimides Derivatives (PBIs) are typical semiconductor materials. The electronic structures of PBIs were successfully investigated by density functions theory (DFT). The computational results were in the good accordance with the experimental UV-vis spectra. Additionally, the electronic structure and the variational UV-vis absorption spectra of PBIs were explained.

CHANGES INDUCED IN THE SURFACE ELECTRONIC STRUCTURE OF Be(0001) AFTER Si ADSORPTION

2002 ◽  
Vol 09 (02) ◽  
pp. 687-691
Author(s):  
L. I. JOHANSSON ◽  
C. VIROJANADARA ◽  
T. BALASUBRAMANIAN
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Band Gap ◽  
Electronic Properties ◽  
Surface State ◽  
Core Level ◽  
Clean Surface ◽  
Core Level Spectrum ◽  
Surface Band ◽  
Surface Electronic Structure

A study of effects induced in the Be 1s core level spectrum and in the surface band structure after Si adsorption on Be(0001) is reported. The changes in the Be 1s spectrum are quite dramatic. The number of resolvable surface components and the magnitude of the shifts do decrease and the relative intensities of the shifted components are drastically different compared to the clean surface. The surface band structure is also strongly affected after Si adsorption and annealing. At [Formula: see text] the surface state is found to move down from 2.8 to 4.1 eV. The band also splits at around 0.5 Å-1 along both the [Formula: see text] and [Formula: see text] directions. At [Formula: see text] and beyond [Formula: see text] only one surface state is observed in the band gap instead of the two for the clean surface. Our findings indicate that a fairly small amount of Si in the outer atomic layers strongly modifies the electronic properties of these layers.

The unexpected effect of vacancies and wrinkling on the electronic properties of MoS2 layers

2019 ◽  
Vol 21 (44) ◽  
pp. 24731-24739 ◽  
Author(s):  
Fábio R. Negreiros ◽  
Germán J. Soldano ◽  
Sergio Fuentes ◽  
Trino Zepeda ◽  
Miguel José-Yacamán ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Properties ◽  
Theoretical Approach ◽  
2D Material ◽  
Unexpected Effect

We report a combined experimental/theoretical approach to study the connection of S-vacancies and wrinkling on MoS2 layers, and how this feature produces significant changes in the electronic structure and reactivity of this 2D material.

Electronic Structure vs Phase in Al3V

1988 ◽  
Vol 141 ◽  
Author(s):  
J.-H. Xu
Keyword(s):  
Electronic Structure ◽  
Bulk Modulus ◽  
Total Energy ◽  
Crystal Structures ◽  
Lattice Constant ◽  
Density Of States ◽  
Phase Stability ◽  
Local Density ◽  
Young Modulus ◽  
Good Agreement

AbstractThe electronic structure of Al3V vs its two different crystal structures (DO22 and Ll2) were investigated using local density total energy approach. The calculated results of the total energy showed that in Al3V the tetragonal DO22 phase is energetically favored as compared to the cubic Ll2 phase, the total energy in the former case is about 60 mRy/F.U. lower than that in the later case. The calculated lattice constant (a=3.72 Å, c=8.20 Å) is in fairly good agreement with experiment (a=3.778 Å, c=8.326 Å),and the bulk modulus (1.3 Mbar) is comparable with the experimental Young modulus (150 GPa) for Al3Ti. Furthermore, it is interesting to note that the density of states at EF in the tetragonal DO22 phase (0.14 states/eV-F.U.) is about one order magnitude smaller than that in the Ll2 phase (2.89 states/eV-F.U.). The electronic structure of Al3V seems to be fairly satisfactory in explaining its phase stability.

Simulation of Vacancy Pairs in GaN Using Tight-Binding Molecular Dynamics

1997 ◽  
Vol 482 ◽  
Author(s):  
Derrick E. Boucher ◽  
Zoltán A. Gál ◽  
Gary G. DeLeo ◽  
W. Beall Fowler
Keyword(s):  
Molecular Dynamics ◽  
Electronic Structure ◽  
Total Energy ◽  
Formation Energy ◽  
Tight Binding ◽  
Md Simulations ◽  
Shallow Donor ◽  
Shallow Acceptor ◽  
Structure Geometry ◽  
Donor Character

AbstractThe electronic structure, geometry and energetics of Ga vacancy pairs and N vacancy pairs in both wurtzite and zincblende GaN are investigated via molecular dynamics (MD) simulations using an empirical tight-binding (TB) model with total energy capabilities and supercells containing up to 216 atoms. Our calculations suggest that, by pairing, N vacancies, which in isolation act as shallow donors, can lower their collective formation energy by about 5 eV. In doing so, however, these N vacancies lose their shallow-donor character as the lattice relaxes in response to this aggregation. Contrasting with the N vacancies, the Ga vacancies are found to retain their isolated shallow acceptor behavior and do not gain significant energy upon aggregation. The possible implications for larger aggregate defects are discussed.

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