scholarly journals Structural and Electronic Properties of Frenkel and Schottky Defects at the MgO{100} Surface: Spin Polarization, Mid-Band Gap States, and Charge Trapping at Vacancy Sites

2019 ◽  
Vol 123 (23) ◽  
pp. 14408-14420 ◽  
Author(s):  
Heleen van Gog ◽  
Marijn A. van Huis
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Spin Polarization ◽  
Charge Trapping ◽  
Structural And Electronic Properties ◽  
Surface Spin ◽  
Gap States

scholarly journals Tunable Electronic Properties of Lateral Monolayer Transition Metal Dichalcogenide Superlattice Nanoribbons

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 534
Author(s):  
Jinhua Wang ◽  
Gyaneshwar P. Srivastava
Keyword(s):  
Transition Metal ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Valence Band Maximum ◽  
Impurity Level ◽  
Asymmetric Structure ◽  
Transition Metal Dichalcogenide ◽  
Structural And Electronic Properties ◽  
Gap States

The structural stability and structural and electronic properties of lateral monolayer transition metal chalcogenide superlattice zigzag and armchair nanoribbons have been studied by employing a first-principles method based on the density functional theory. The main focus is to study the effects of varying the width and periodicity of nanoribbon, varying cationic and anionic elements of superlattice parent compounds, biaxial strain, and nanoribbon edge passivation with different elements. The band gap opens up when the (MoS2)3/(WS2)3 and (MoS2)3/(MoTe2)3 armchair nanoribbons are passivated by H, S and O atoms. The H and O co-passivated (MoS2)3/(WS2)3 armchair nanoribbon exhibits higher energy band gap. The band gap with the edge S vacancy connecting to the W atom is much smaller than the S vacancy connecting to the Mo atom. Small band gaps are obtained for both edge and inside Mo vacancies. There is a clear difference in the band gap states between inside and edge Mo vacancies for symmetric nanoribbon structure, while there is only a slight difference for asymmetric structure. The electronic orbitals of atoms around Mo vacancy play an important role in determining the valence band maximum, conduction band minimum, and impurity level in the band gap.

scholarly journals An Experimental and Theoretical Study on the Effect of Silver Nanoparticles Concentration on the Structural, Morphological, Optical, and Electronic Properties of TiO2 Nanocrystals

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1488
Author(s):  
Faheem Ahmed ◽  
Mohammed Benali Kanoun ◽  
Chawki Awada ◽  
Christian Jonin ◽  
Pierre-Francois Brevet
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Anatase Phase ◽  
Density Functional Theory Calculations ◽  
Tio2 Nanocrystals ◽  
Uniform Size ◽  
Chemical Route ◽  
Structural And Electronic Properties ◽  
Nanoparticles Concentration ◽  
Gap States

In this work, pure and silver (Ag)-loaded TiO2 nanocrystals (NCs) with various concentrations of Ag were prepared by soft chemical route and the effect of Ag nanoparticles (NPs) on the functional properties of TiO2 was studied. X-ray diffraction (XRD) and Raman studies confirmed that the synthesized product had single-phase nature and high crystalline quality. The crystallite size was decreased from 18.3 nm to 13.9 nm with the increasing in concentration of Ag in TiO2 NCs. FESEM micrographs showed that the pure and AgNPs-loaded TiO2 have spherical morphology and uniform size distribution with the size ranging from 20 to 10 nm. Raman spectroscopy performed on pure and AgNPs-loaded TiO2 confirms the presence of anatase phase and AgNPs. Optical properties show the characteristics peaks of TiO2 and the shifting of the peaks position was observed by changing the concentration of Ag. The tuning of bandgap was found to be observed with the increase in Ag, which could be ascribed to the synergistic effect between silver and TiO2 NCs. Density functional theory calculations are carried out for different Ag series of doped TiO2 lattices to simulate the structural and electronic properties. The analysis of the electronic structures show that Ag loading induces new localized gap states around the Fermi level. Moreover, the introduction of dopant states in the gap region owing to Ag doping can be convenient to shift the absorption edge of pristine TiO2 through visible light.

COMPARATIVE STUDY OF THE STRUCTURAL AND ELECTRONIC PROPERTIES OF BN(5, 5) AND C(5, 5) NANOTUBES UNDER PRESSURE

2010 ◽  
Vol 24 (24) ◽  
pp. 4851-4859
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
GANG CHEN ◽  
QILI CHEN ◽  
MIAO WAN ◽  
...  
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Charge Density ◽  
Band Gap ◽  
Electronic Properties ◽  
Cross Section ◽  
First Principles ◽  
First Principles Calculations ◽  
Zinc Blende ◽  
Structural And Electronic Properties

The structural and electronic properties of BN(5, 5) and C(5, 5) nanotubes under pressure are studied by using first principles calculations. In our study range, BN(5, 5) undergoes obvious elliptical distortion, while for C(5, 5) the cross section first becomes an ellipse and then, under further pressure, is flattened. The band gap of BN(5, 5) decreases with increasing pressure, which is inverse to that of zinc blende BN, whereas for C(5, 5) the metallicity is always preserved under high pressure. The population of charge density indicates that intertube bonding is formed under pressure. We also find that BN(5, 5) may collapse, and a new polymer material based on C(5, 5) is formed by applying pressure.

Structural and Electronic Properties of Oxygen Vacancies in Monoclinic HfO2

2007 ◽  
Vol 996 ◽  
Author(s):  
Peter Broqvist ◽  
Alfredo Pasquarello
Keyword(s):  
Oxygen Vacancy ◽  
Optical Absorption ◽  
Total Energy ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Structural And Electronic Properties ◽  
Defect Levels ◽  
Hybrid Density Functional

AbstractWe study structural and electronic properties of the oxygen vacancy in monoclinic HfO2 for five different charge states. We use a hybrid density functional to accurately reproduce the experimental band gap. To compare with measured defect levels, we determine total-energy differences appropriate to the considered experiments. Our results show that the oxygen vacancy can consistently account for the defect levels observed in optical absorption, direct electron injection, and trap-assisted conduction experiments.

scholarly journals Organically interconnected graphene flakes: A flexible 3-D material with tunable electronic bandgap

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
E. Klontzas ◽  
E. Tylianakis ◽  
V. Varshney ◽  
A. K. Roy ◽  
G. E. Froudakis
Keyword(s):  
Chemical Composition ◽  
Band Gap ◽  
Electronic Properties ◽  
Flexible Electronics ◽  
Density Functional ◽  
Organic Molecule ◽  
Tight Binding ◽  
Structural And Electronic Properties ◽  
Graphene Flakes ◽  
Band Gap Tuning

Abstract The structural and electronic properties of molecularly pillared graphene sheets were explored by performing Density Functional based Tight Binding calculations. Several different architectures were generated by varying the density of the pillars, the chemical composition of the organic molecule acting as a pillar and the pillar distribution. Our results show that by changing the pillars density and distribution we can tune the band gap transforming graphene from metallic to semiconducting in a continuous way. In addition, the chemical composition of the pillars affects the band gap in a lesser extent by introducing additional states in the valence or the conduction band and can act as a fine band gap tuning. These unique electronic properties controlled by design, makes Mollecular Pillared Graphene an excellent material for flexible electronics.

Structural and Electronic Properties of (CdTe)1−x(In2Te3)x Films Grown by Close-spaced vapor Transport Combined with Free Evaporation

2000 ◽  
Vol 15 (8) ◽  
pp. 1811-1815 ◽  
Author(s):  
M. Zapata-Torres ◽  
Y. P. Mascarenhas ◽  
M. A. Santana-Aranda ◽  
J. Luyo-Alvarado ◽  
M. Melé-Lirandez ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Single Phase ◽  
Vapor Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
Transmission Measurements

The structural and electronic properties of (CdTe)1−x(In2Te3)x thin films as a function of substrate temperature were studied using x-ray diffraction, energy dispersive x-ray analysis, and Raman, transmission, and modulated transmission spectroscopies. The films were grown by the close-spaced vapor transport technique combined with free evaporation; CdTe and In2Te3 were used as sources. From x-ray diffraction the presence of mixed phases and differences in composition were detected, and good correlation with Raman spectroscopy was found. Transmission spectroscopy suggested the possibility of a modulation of the band gap of the alloy from a value as low as 0.5 eV up to 1.5 eV. Single-phase films presented a direct band gap of around 1.15 eV, as obtained from modulated transmission measurements.

Structural and electronic properties of narrow-band-gap semiconductors: InP, InAs, and InSb

1990 ◽  
Vol 41 (17) ◽  
pp. 12079-12085 ◽  
Author(s):  
S. Massidda ◽  
A. Continenza ◽  
A. J. Freeman ◽  
T. M. de Pascale ◽  
F. Meloni ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Narrow Band ◽  
Structural And Electronic Properties ◽  
Narrow Band Gap Semiconductors

Cerium-induced changes in the π-band of graphene

RSC Advances ◽  
2016 ◽  
Vol 6 (115) ◽  
pp. 114219-114223 ◽  
Author(s):  
Jingul Kim ◽  
Paengro Lee ◽  
Mintae Ryu ◽  
Heemin Park ◽  
Jinwook Chung
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Temperature Dependent ◽  
Layer Graphene ◽  
Structural And Electronic Properties ◽  
Induced Changes

By doping magnetic Ce atoms on a single layer graphene, we report a new and efficient means of modifying structural and electronic properties of graphene that opens a temperature-dependent band gap of size up to 0.5 eV.

scholarly journals Theoretical Prediction of the Structural and Electronic Properties of a Single Layer Graphene-like Two-dimensional Janus GaInSTe

2021 ◽  
Vol 37 (2) ◽  
Author(s):  
Nguyen Van Chuong ◽  
Nguyen Ngoc Hieu ◽  
Nguyen Van Hieu
Keyword(s):  
Electric Field ◽  
Band Gap ◽  
Electronic Properties ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Two Dimensional ◽  
Direct Band Gap ◽  
Structural And Electronic Properties ◽  
Direct Band ◽  
New Type

This paper constructs a new type of two-dimensional graphene-like Janus GaInSTe monolayer and systematically investigates its structural and electronic properties as well as the effect of external electric field using first-principles calculations. In the ground state, Janus GaInSTe monolayer is dynamically stable with no imaginary frequencies in its phonon spectrum and possesses a direct band gap semiconductor. The band gap of Janus GaInSTe monolayer can be tuned by applying an electric field, which leads the different transitions from semiconductor to metal, and from indirect to direct band gap. These findings show a great potential application of Janus GaInSTe material for designing next-generation devices.

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