Acceptor Binding Energies in GaN and AIN

1997 ◽  
Vol 482 ◽  
Author(s):  
Francisco Mireles ◽  
Sergio E. Ulloa
Keyword(s):  
Binding Energy ◽  
Effective Mass ◽  
Crystalline Phase ◽  
Energy Shift ◽  
Binding Energies ◽  
Bulk Crystals ◽  
Shallow Acceptors ◽  
Crystal Phases ◽  
Binding Energy Calculations ◽  
Good Agreement

AbstractWe present binding energy calculations for Mg, Zn, and C substitutional shallow acceptors in GaN and AIN for both, wurtzite (WZ) and zincblende (ZB) crystal phases. The calculations are performed within the effective mass theory through the 6 × 6 Rashba-Sheka-Pikus and the Luttinger- Kohn matrix Hamiltonians for WZ and ZB bulk crystals, respectively. An analytic representation for the pseudopotential is used to introduce the nature of the impurity atom. The energy shift due to polaron effects is also considered in this approach. The estimated ionization energies are in good agreement with those reported experimentally and those reported theoretically employing other methods. We find that the binding energies for ZB GaN acceptors are shallower than the corresponding impurities in the WZ crystalline phase. The binding energy dependence upon the crystal field splitting in the WZ compounds is analyzed.

A DFT study of spherands containing five anisyl groups — Highly preorganized to bind the alkali metal

2006 ◽  
Vol 84 (8) ◽  
pp. 1045-1049 ◽  
Author(s):  
Shabaan AK Elroby ◽  
Kyu Hwan Lee ◽  
Seung Joo Cho ◽  
Alan Hinchliffe
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Ionic Radius ◽  
Binding Energies ◽  
Cavity Size ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Good Agreement

Although anisyl units are basically poor ligands for metal ions, the rigid placements of their oxygens during synthesis rather than during complexation are undoubtedly responsible for the enhanced binding and selectivity of the spherand. We used standard B3LYP/6-31G** (5d) density functional theory (DFT) to investigate the complexation between spherands containing five anisyl groups, with CH2–O–CH2 (2) and CH2–S–CH2 (3) units in an 18-membered macrocyclic ring, and the cationic guests (Li+, Na+, and K+). Our geometric structure results for spherands 1, 2, and 3 are in good agreement with the previously reported X-ray diffraction data. The absolute values of the binding energy of all the spherands are inversely proportional to the ionic radius of the guests. The results, taken as a whole, show that replacement of one anisyl group by CH2–O–CH2 (2) and CH2–S–CH2 (3) makes the cavity bigger and less preorganized. In addition, both the binding and specificity decrease for small ions. The spherands 2 and 3 appear beautifully preorganized to bind all guests, so it is not surprising that their binding energies are close to the parent spherand 1. Interestingly, there is a clear linear relation between the radius of the cavity and the binding energy (R2 = 0.999).Key words: spherands, preorganization, density functional theory, binding energy, cavity size.

The electrostatic calculation of molecurlar energies - III. The binding energies of saturated molecules

1954 ◽  
Vol 226 (1165) ◽  
pp. 193-205 ◽  
Keyword(s):  
Binding Energy ◽  
Valence Bond ◽  
Binding Energies ◽  
Wave Functions ◽  
Complex Molecules ◽  
Electron Orbital ◽  
Hydride Molecule ◽  
Paired Electron ◽  
Bond Functions ◽  
Good Agreement

A technique for calculating the binding energy of any saturated molecule is developed.The method is based on an application of the electrostatic theorem, discussed in earlier parts, to paired-electron orbital wave functions.These wave functions include both molecular-orbital and valence-bond functions as special cases.The resulting numerical computations are sufficiently simple to be carried through without approximation even for complex molecules. The method is applied to the lithium molecule and the lithium hydride molecule, and yields results in good agreement with experiment. The choice of wave functions for calculations on other molecules is discussed.

scholarly journals Impact of QW coupling on the binding energy in InGaN/GaN under the effects of the size, the impurity and the internal composition

2020 ◽  
Vol 330 ◽  
pp. 01012
Author(s):  
Walid Belaid ◽  
Haddou El Ghazi ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Binding Energy ◽  
Quantum Wells ◽  
Effective Mass ◽  
Variational Approach ◽  
Shallow Donor ◽  
Donor Impurity ◽  
Coupled Quantum Wells ◽  
Surrounding Matrix ◽  
Main Effect ◽  
Good Agreement

In the present paper, the binding energy of hydrogenic shallow-donor impurity in simple and double coupled quantum wells based on unstrained wurtzite (In,Ga)N/GaN is investigated. Considering the effective-mass and dielectric mismatches between the well and its surrounding matrix, the numerical calculations are performed within the framework of the parabolic band and the single band effective-mass approximations under the finite potential barrier using finite element method (FEM). According to our results, it appears that the main effect of the wells coupling is to enhance the binding energy. It is also obtained that the binding energy is strongly sensitive to the internal and external parameters and can be adjusted by the quantum well/barrier width, the impurity position and the internal Indium composition. Our results are in good agreement with the finding especially for those obtained by the variational approach.

scholarly journals Binding Energy of Exciton in Quantum Dots with the Central-cell Correction Depending on the Dot Sizes

2007 ◽  
Vol 14 (2) ◽  
pp. 95-99 ◽  
Author(s):  
To Thi Thao ◽  
Nguyen Ai Viet
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Variational Methods ◽  
Effective Mass ◽  
Short Range ◽  
Central Cell ◽  
Short Range Potential ◽  
Two Parameters ◽  
Center Cell ◽  
Good Agreement

The binding energy of exciton in quantum dots with a parabolic confinement potential was calculated by variational methods beyond the Kohn-Luttinger effective mass theory, when the central-cell correction was taken into account.We have assumed that a short range potential with two parameters for strength and range for exciton, representing the center-cell effect also depends on dot size. Our result is in good agreement with experiment.

scholarly journals Electrostatically assisted macroion association

2021 ◽  
Vol 24 (3) ◽  
pp. 33502
Author(s):  
J. Reščiš
Keyword(s):  
Monte Carlo ◽  
Molecular Docking ◽  
Binding Energy ◽  
Short Range ◽  
Dynamic Equilibrium ◽  
Model System ◽  
Binding Energies ◽  
Effective Attraction ◽  
Theoretical Results ◽  
Good Agreement

A model system of highly asymmetric polyelectrolyte with directional short-range attractive interactions was studied by canonical Monte Carlo computer simulations. Comparison of MC data with previously published theoretical results shows good agreement. For moderate values of binding energies, which matches those of molecular docking, a dynamic equilibrium between free and dimerized macroions is observed. Fraction of dimerized macroions depends on macroion concentration, binding energy magnitude, and on the valency of small counterions. Divalent counterions induce an effective attraction between macroions and enhance dimerization. This effect is most notable at low to moderate macroion concentrations.

BINDING ENERGY OF ACCEPTORS IN SEMIMAGNETIC QUANTUM DOTS

2006 ◽  
Vol 05 (01) ◽  
pp. 173-181 ◽  
Author(s):  
A. JOHN PETER
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Bound States ◽  
Mean Field Theory ◽  
Mean Field ◽  
Binding Energies ◽  
Mass Approximation ◽  
Variational Calculations ◽  
Shallow Acceptors ◽  
Peak Value

The binding energies of shallow acceptors in Cd 1-x in Mn x in Te/ Cd 1-x out Mn x out Te quantum dots are calculated in the presence of external magnetic fields. Variational calculations are performed within effective mass approximation. The results show that the impurity binding energy (i) increases with the reduction in dot sizes, (ii) decreases with the magnetic field is increased for a given dot, and (iii) reaches a peak value as the dot radius decreases and then diminishes to a limiting value corresponding to the radius for which there are no bound states in the quantum dot. Spin polaronic shifts are estimated with the acceptor envelope function using a mean field theory. These results are compared with the existing literatures.

Simultaneous effects of pressure and temperature on excitons in Pöschl–Teller quantum well

2017 ◽  
Vol 31 (08) ◽  
pp. 1750050 ◽  
Author(s):  
A. Anitha ◽  
M. Arulmozhi
Keyword(s):  
Binding Energy ◽  
Quantum Well ◽  
Effective Mass ◽  
Heavy Hole ◽  
Light Hole ◽  
Binding Energies ◽  
Exciton Binding Energy ◽  
Effective Mass Approximation ◽  
Mass Approximation ◽  
Asymmetric Configuration

Binding energies of the heavy hole and light hole exciton in a quantum well with Pöschl–Teller (PT) potential composed of GaAs have been studied variationally within effective mass approximation. The effects of pressure and temperature on exciton binding energy are analyzed individually and also simultaneously for symmetric and asymmetric configuration of the well. The results show that exciton binding energy (i) decreases as the well width increases, (ii) increases with pressure and (iii) decreases with temperature. Simultaneous effects of these perturbations lead to more binding of the exciton. The results are compared with the existing literature.

Residual np-interaction and mass predictions in transfermium region

2021 ◽  
pp. 2150025
Author(s):  
E. V. Vladimirova ◽  
B. S. Ishkhanov ◽  
M. V. Simonov ◽  
S. V. Sidorov ◽  
T. Yu. Tretyakova
Keyword(s):  
Experimental Data ◽  
Binding Energy ◽  
Mass Relation ◽  
Energy Calculations ◽  
Local Mass ◽  
Nuclear Masses ◽  
Text Interaction ◽  
Binding Energy Calculations ◽  
Relation Approach ◽  
Good Agreement

We study the consistency of local mass relation approach in its application to prediction of nuclear masses in the region of superheavy elements. Binding energy calculations are carried out for nuclei with [Formula: see text] using formulas for evaluation of residual [Formula: see text]-interaction. The results are found to be in good agreement with the experimental data AME2016. We also make predictions for characteristics of [Formula: see text]-decay in isotopes [Formula: see text]–106, [Formula: see text]–157.

scholarly journals np-Pair Correlations in the Isovector Pairing Model

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1405
Author(s):  
Feng Pan ◽  
Yingwen He ◽  
Lianrong Dai ◽  
Chong Qi ◽  
Jerry P. Draayer
Keyword(s):  
Binding Energy ◽  
Occupation Number ◽  
Mean Field ◽  
Energy Difference ◽  
Binding Energies ◽  
Pair Correlations ◽  
Isospin Symmetry Breaking ◽  
Pairing Model ◽  
Proton Pairing ◽  
Spin Basis

A diagonalization scheme for the shell model mean-field plus isovector pairing Hamiltonian in the O(5) tensor product basis of the quasi-spin SUΛ(2) ⊗ SUI(2) chain is proposed. The advantage of the diagonalization scheme lies in the fact that not only can the isospin-conserved, charge-independent isovector pairing interaction be analyzed, but also the isospin symmetry breaking cases. More importantly, the number operator of the np-pairs can be realized in this neutron and proton quasi-spin basis, with which the np-pair occupation number and its fluctuation at the J = 0+ ground state of the model can be evaluated. As examples of the application, binding energies and low-lying J = 0+ excited states of the even–even and odd–odd N∼Z ds-shell nuclei are fit in the model with the charge-independent approximation, from which the neutron–proton pairing contribution to the binding energy in the ds-shell nuclei is estimated. It is observed that the decrease in the double binding-energy difference for the odd–odd nuclei is mainly due to the symmetry energy and Wigner energy contribution to the binding energy that alter the pairing staggering patten. The np-pair amplitudes in the np-pair stripping or picking-up process of these N = Z nuclei are also calculated.

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