PRESSURE DEPENDENCE OF OPTO-ELECTRONIC PROPERTIES IN ZnSxSe1-x

2006 ◽  
Vol 20 (28) ◽  
pp. 4807-4820 ◽  
Author(s):  
F. BENMAKHLOUF ◽  
N. BOUARISSA
Keyword(s):  
Electronic Properties ◽  
Optical Constants ◽  
Alloy Composition ◽  
Electronic Devices ◽  
Pressure Coefficient ◽  
Virtual Crystal Approximation ◽  
High Frequency Dielectric Constant ◽  
Empirical Pseudopotential Method ◽  
Zinc Blende ◽  
Semiconducting Alloys

We present an investigation of the electronic properties and optical constants of zinc-blende ZnS x Se 1-x semiconducting alloys at normal and under hydrostatic pressure up to 20 kbar. For this purpose, we used an empirical pseudopotential method within the virtual crystal approximation. The effects of alloy composition are taken into consideration in the calculation, which improves significantly the bandgap bowing parameters with respect to the experiment. Results regarding the composition and pressure dependences of energy bandgaps, electron valence and conduction charge distributions, optical high-frequency dielectric constant and its linear pressure coefficient are presented and discussed. The information derived from the present study may be useful for the development of opto-electronic devices that operate in the blue/green spectral range.

Beryllium Effect on the Energy Band Gaps and the Electronic Charge Density of the Alloy (Be, Cd) Se

2019 ◽  
Vol 297 ◽  
pp. 131-142
Author(s):  
Hadjer Saheb ◽  
Abderrachid Bechiri
Keyword(s):  
Charge Density ◽  
Electronic Band Structure ◽  
Electronic Charge ◽  
Electronic Charge Density ◽  
Virtual Crystal Approximation ◽  
Electronic Band ◽  
Empirical Pseudopotential Method ◽  
Zinc Blende ◽  
Disorder Effect ◽  
Zinc Blende Structure

In the present study, we have computed the electronic band structure and electronic charge density of the alloy (Be, Cd)Se in the zinc-blende structure; using the local Empirical Pseudopotential Method (EPM), which takes into account the disorder effect into the Virtual Crystal Approximation (VCA) by introducing an effective potential disorder. The obtained results show a reasonable agreement with the available experimental data. Detailed plots of the valence charge distribution along the [111] direction and in the (110) plane are also presented and discussed.

scholarly journals Influence of Pressure on the Mechanical and Electronic Properties of Wurtzite and Zinc-Blende GaN Crystals

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 428
Author(s):  
Hongbo Qin ◽  
Tianfeng Kuang ◽  
Xinghe Luan ◽  
Wangyun Li ◽  
Jing Xiao ◽  
...  
Keyword(s):  
Shear Modulus ◽  
Bulk Modulus ◽  
Electronic Properties ◽  
Single Crystals ◽  
High Pressures ◽  
Elastic Anisotropy ◽  
Pressure Coefficient ◽  
Shear Moduli ◽  
Zinc Blende ◽  
Unit Cells

The mechanical and electronic properties of two GaN crystals, wurtzite and zinc-blende GaN, under various hydrostatic pressures were investigated using first principles calculations. The results show that the lattice constants of the two GaN crystals calculated in this study are close to previous experimental results, and the two GaN crystals are stable under hydrostatic pressures up to 40 GPa. The pressure presents extremely similar trend effect on the volumes of unit cells and average Ga-N bond lengths of the two GaN crystals. The bulk modulus increases while the shear modulus decreases with the increase in pressure, resulting in the significant increase of the ratios of bulk moduli to shear moduli for the two GaN polycrystals. Different with the monotonic changes of bulk and shear moduli, the elastic moduli of the two GaN polycrystals may increase at first and then decrease with increasing pressure. The two GaN crystals are brittle materials at zero pressure, while they may exhibit ductile behaviour under high pressures. Moreover, the increase in pressure raises the elastic anisotropy of GaN crystals, and the anisotropy factors of the two GaN single crystals are quite different. Different with the obvious directional dependences of elastic modulus, shear modulus and Poisson’s ratio of the two GaN single crystals, there is no anisotropy for bulk modulus, especially for that of zinc-blende GaN. Furthermore, the band gaps of GaN crystals increase with increasing pressure, and zinc-blende GaN has a larger pressure coefficient. To further understand the pressure effect on the band gap, the band structure and density of states (DOSs) of GaN crystals were also analysed in this study.

Intercalation of First Row Transition Metals inside Covalent-Organic Frameworks (COF): a Strategy to Fine Tune the Electronic Properties of Porous Crystalline Materials

2018 ◽  
Author(s):  
Srimanta Pakhira ◽  
Jose Mendoza-Cortes
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Electronic Properties ◽  
High Surface ◽  
Electronic Devices ◽  
High Surface Area ◽  
Main Role ◽  
Covalent Organic Frameworks ◽  
Porous Network ◽  
Crystalline Materials

<div>Covalent organic frameworks (COFs) have emerged as an important class of nano-porous crystalline materials with many potential applications. They are intriguing platforms for the design of porous skeletons with special functionality at the molecular level. However, despite their extraordinary properties, it is difficult to control their electronic properties, thus hindering the potential implementation in electronic devices. A new form of nanoporous material, COFs intercalated with first row transition metal is proposed to address this fundamental drawback - the lack of electronic tunability. Using first-principles calculations, we have designed 31 new COF materials <i>in-silico</i> by intercalating all of the first row transition metals (TMs) with boroxine-linked and triazine-linked COFs: COF-TM-x (where TM=Sc-Zn and x=3-5). This is a significant addition considering that only 187 experimentally COFs structures has been reported and characterized so far. We have investigated their structure and electronic properties. Specifically, we predict that COF's band gap and density of states (DOSs) can be controlled by intercalating first row transition metal atoms (TM: Sc - Zn) and fine tuned by the concentration of TMs. We also found that the $d$-subshell electron density of the TMs plays the main role in determining the electronic properties of the COFs. Thus intercalated-COFs provide a new strategy to control the electronic properties of materials within a porous network. This work opens up new avenues for the design of TM-intercalated materials with promising future applications in nanoporous electronic devices, where a high surface area coupled with fine-tuned electronic properties are desired.</div>

Zinc-blende ZnS under pressure: predicted electronic properties

2003 ◽  
Vol 47 (8) ◽  
pp. 1335-1338 ◽  
Author(s):  
F. Benmakhlouf ◽  
A. Bechiri ◽  
N. Bouarissa
Keyword(s):  
Electronic Properties ◽  
Zinc Blende

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.

Tuning of electronic properties in IV–VI colloidal nanostructures by alloy composition and architecture

Nanoscale ◽  
2013 ◽  
Vol 5 (17) ◽  
pp. 7724 ◽  
Author(s):  
Aldona Sashchiuk ◽  
Diana Yanover ◽  
Anna Rubin-Brusilovski ◽  
Georgy I. Maikov ◽  
Richard K. Čapek ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Alloy Composition

scholarly journals Simplex Algorithm for Band Structure Calculation of Noncubic Symmetry Semiconductors: Application to III-nitride Binaries and Alloys

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 63-68 ◽  
Author(s):  
Enrico Ghillino ◽  
Carlo Garetto ◽  
Michele Goano ◽  
Giovanni Ghione ◽  
Enrico Bellotti ◽  
...  
Keyword(s):  
Band Structure ◽  
Simplex Algorithm ◽  
Initial Guess ◽  
Phase Iii ◽  
Band Structure Calculation ◽  
Wurtzite Phase ◽  
Empirical Pseudopotential Method ◽  
Zinc Blende

A set of software tools for the determination of the band structure of zinc-blende, wurtzite, 4H, and 6H semiconductors is presented. A state of the art implementation of the nonlocal empirical pseudopotential method has been coupled with a robust simplex algorithm for the optimization of the adjustable parameters of the model potentials. This computational core has been integrated with an array of Matlab functions, providing interactive functionalities for defining the initial guess of the atomic pseudopotentials, checking the convergence of the optimization process, plotting the resulting band structure, and computing detailed information about any local minimum. The results obtained for wurtzite-phase III-nitrides (ALN, GaN, InN) are presented as a relevant case study.

The Electronic Properties of Epitaxial Calcium Fluoride-Silicon Structures

1985 ◽  
Vol 54 ◽  
Author(s):  
T. P. Smith ◽  
J. M. Phillips ◽  
R. People ◽  
J. M. Gibson ◽  
L. Pfeiffer ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Material Properties ◽  
Calcium Fluoride ◽  
Minority Carrier ◽  
Electronic Devices ◽  
Epitaxial Films ◽  
High Quality ◽  
Silicon Structures

ABSTRACTThe characterization of electronic devices using epitaxial CaF2 on Si is described. In addition, the growth and annealing techniques used to obtain high quality epitaxial films are discussed. In particular, the results of using rapid thermal annealing to improve the epitaxial quality of CaF2 films are presented in detail.The electronic and electrical properties of these structures are very promising. Epitaxial CaF2 films with breakdown fields as high as 3 × 106 V/cm and interface trap densities as low as 7 × 1010cm-2eV-1 have been fabricated. In addition, minority carrier dominated trapping has been observed at the CaF2 /Si interface. Finally, the material properties of these structures, as determined by Rutherford backscattering, channeling, and electron microscopy, are discussed and correlated with their electronic properties.

A detailed first principle study on the structural, elastic, and electronic properties of indium arsenide (InAs) under induced pressure

2016 ◽  
Vol 94 (3) ◽  
pp. 254-261
Author(s):  
Kh. Kabita ◽  
M. Jameson ◽  
B.I. Sharma ◽  
R.K. Brojen ◽  
R.K. Thapa
Keyword(s):  
Electronic Properties ◽  
Indium Arsenide ◽  
Rock Salt ◽  
Density Functional ◽  
Structural Phase ◽  
Theoretical Data ◽  
Partial Density ◽  
Electronic Band ◽  
Zinc Blende ◽  
Salt Structure

An ab initio calculation of the structural, elastic, and electronic properties of indium arsenide (InAs) under induced pressure is investigated using density functional theory with modified Becke–Johnson potential within the generalised gradient approximation of the Perdew–Burke–Ernzerhof scheme. The lattice parameters are found to be in good agreement with experimental and other theoretical data. The pressure-induced structural phase transition of InAs zinc blende to rock salt structure is found to occur at 4.7 GPa pressure with a 17.2% of volume collapse. The elastic properties of both the zinc blende and rock salt structures at different pressures are studied. The electronic band structures at different pressures for both the structures are investigated using the total and partial density of states. The energy band gap of the InAs zinc blende phase is increased with increasing pressure while in rock salt the phase the conduction band crosses towards the valence band and thus shows metallic behaviour.

Electronic properties of zinc-blende Scx Ga1−xN

2006 ◽  
Vol 243 (12) ◽  
pp. 2780-2787 ◽  
Author(s):  
A. Ben Fredj ◽  
Y. Oussaifi ◽  
N. Bouarissa ◽  
M. Said
Keyword(s):  
Electronic Properties ◽  
Zinc Blende
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