Fractal dimension method for exciton in cylindrical GaAs/AlxGa1−xAs core-shell-cap nanowires

By use of the fractal dimension method, the binding energies of heavy-hole exciton and light-hole exciton in cylindrical GaAs/Al[Formula: see text]Ga[Formula: see text]As core-shell-cap nanowire are explored. In this study, the exciton is confined in GaAs shell of the GaAs/Al[Formula: see text]Ga[Formula: see text]As core-shell-cap nanowire for a given aluminum concentration of [Formula: see text][Formula: see text]=[Formula: see text]0.3. The numerical results of heavy-hole exciton binding energy, light-hole exciton binding energy and fractal dimension parameter are worked out as functions of shell width and core radius. It has been shown by the calculated results that heavy-hole exciton binding energy and light-hole exciton binding energy firstly increase and then decrease as the shell width increases. When the core radius increases, both the heavy-hole exciton binding energy and light-hole exciton binding energy increase gradually. Exciton problems in GaAs shell of the cylindrical GaAs/Al[Formula: see text]Ga[Formula: see text]As core-shell-cap nanowire are solved in a simple manner to avoid complex and lengthy calculations by using the fractal dimension method.

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

International Journal of Modern Physics B ◽

10.1142/s0217979217500503 ◽

2017 ◽

Vol 31 (08) ◽

pp. 1750050 ◽

Cited By ~ 1

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.

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The binding energies of atomic nuclei III. Nuclear forces and the ground state of oxygen 16

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1959.0187 ◽

1959 ◽

Vol 253 (1273) ◽

pp. 186-198 ◽

Cited By ~ 12

Keyword(s):

Binding Energy ◽

Electron Scattering ◽

Ground State ◽

Binding Energies ◽

Wave Functions ◽

Unperturbed System ◽

Core Radius ◽

Nuclear Forces ◽

Potential Core ◽

Atomic Nuclei

The r. m. s. radius and the binding energy of oxygen 16 are calculated for several different internueleon potentials. These potentials all fit the low-energy data for two nucleons, they have hard cores of differing radii, and they include the Gammel-Thaler potential (core radius 0·4 fermi). The calculated r. m. s. radii range from 1·5 f for a potential with core radius 0·2 f to 2·0 f for a core radius 0·6 f. The value obtained from electron scattering experiments is 2·65 f. The calculated binding energies range from 256 MeV for a core radius 0·2 f to 118 MeV for core 0·5 f. The experimental value of binding energy is 127·3 MeV. The 25% discrepancy in the calculated r. m. s. radius may be due to the limitations of harmonic oscillator wave functions used in the unperturbed system.

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Exciton binding energies in GaAs films on AlxGa1−xAs substrates

International Journal of Modern Physics B ◽

10.1142/s0217979215502136 ◽

2015 ◽

Vol 29 (30) ◽

pp. 1550213 ◽

Cited By ~ 4

Author(s):

Zhenhua Wu ◽

Lei Chen ◽

Qiang Tian

Keyword(s):

Film Thickness ◽

Significant Influence ◽

Heavy Hole ◽

Dimensional Space ◽

Light Hole ◽

Binding Energies ◽

Substrate Thickness ◽

Dimensional Approach ◽

Anisotropic System ◽

Gaas Films

We use the fractional–dimensional approach (FDA) to study exciton binding energies in GaAs films on [Formula: see text] substrates. In this approach, the Schrödinger equation for a given anisotropic system is solved in a noninteger-dimensional space where the interactions are assumed to occur in an isotropic effective environment. The heavy-hole and light-hole exciton binding energies are calculated as functions of the film thickness and substrate thickness. The numerical results show that both the heavy-hole and light-hole exciton binding energies decrease monotonously as the film thickness increases. When the film thickness and the substrate thickness is relatively small, the change of substrate thickness has comparatively remarkable influence on both heavy-hole and light-hole exciton binding energies. As the substrate thickness increases, both the heavy-hole and light-hole exciton binding energies increase gradually. When the film thickness or the substrate thickness is relatively large, the change of substrate thickness has no significant influence on both heavy-hole and light-hole exciton binding energies.

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Theoretical modelling of exciton binding energy, steady-state and transient optical response of GaN/InGaN/GaN and AlGaN/GaN/AlGaN core–shell nanostructures

Nanotechnology ◽

10.1088/1361-6528/ab1154 ◽

2019 ◽

Vol 30 (27) ◽

pp. 274002 ◽

Cited By ~ 3

Author(s):

Vikas Pendem ◽

Ankit Udai ◽

Tarni Aggarwal ◽

Swaroop Ganguly ◽

Dipankar Saha

Keyword(s):

Steady State ◽

Binding Energy ◽

Optical Response ◽

Exciton Binding Energy ◽

Theoretical Modelling ◽

Core Shell ◽

Shell Nanostructures

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Giant gate-tunable bandgap renormalization and excitonic effects in a 2D semiconductor

Science Advances ◽

10.1126/sciadv.aaw2347 ◽

2019 ◽

Vol 5 (7) ◽

pp. eaaw2347 ◽

Cited By ~ 15

Author(s):

Zhizhan Qiu ◽

Maxim Trushin ◽

Hanyan Fang ◽

Ivan Verzhbitskiy ◽

Shiyuan Gao ◽

...

Keyword(s):

Binding Energy ◽

Single Layer ◽

Scanning Tunneling Spectroscopy ◽

Binding Energies ◽

Exciton Binding Energy ◽

Scanning Tunneling ◽

Full Potential ◽

2D Semiconductors ◽

Wide Range ◽

Excitonic Effects

Understanding the remarkable excitonic effects and controlling the exciton binding energies in two-dimensional (2D) semiconductors are crucial in unlocking their full potential for use in future photonic and optoelectronic devices. Here, we demonstrate large excitonic effects and gate-tunable exciton binding energies in single-layer rhenium diselenide (ReSe2) on a back-gated graphene device. We used scanning tunneling spectroscopy and differential reflectance spectroscopy to measure the quasiparticle electronic and optical bandgap of single-layer ReSe2, respectively, yielding a large exciton binding energy of 520 meV. Further, we achieved continuous tuning of the electronic bandgap and exciton binding energy of monolayer ReSe2 by hundreds of milli–electron volts through electrostatic gating, attributed to tunable Coulomb interactions arising from the gate-controlled free carriers in graphene. Our findings open a new avenue for controlling the bandgap renormalization and exciton binding energies in 2D semiconductors for a wide range of technological applications.

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Assessment of density functional methods for exciton binding energies and related optoelectronic properties

RSC Advances ◽

10.1039/c5ra20085g ◽

2015 ◽

Vol 5 (123) ◽

pp. 101370-101376 ◽

Cited By ~ 30

Author(s):

Jui-Che Lee ◽

Jeng-Da Chai ◽

Shiang-Tai Lin

Keyword(s):

Binding Energy ◽

Density Functional ◽

Mean Absolute Error ◽

Absolute Error ◽

Binding Energies ◽

Optoelectronic Properties ◽

Exciton Binding Energy ◽

Dft Methods ◽

Density Functional Methods ◽

Functional Methods

Mean absolute error (MAE) in exciton binding energy (Eb) from 9 DFT methods against benchmark CCSD and EOM-CCSD.

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PRESSURE EFFECT ON THE INTERFACE EXCITONS IN A TYPE-II ZnTe/CdSe HETEROJUNCTION

Modern Physics Letters B ◽

10.1142/s0217984903006475 ◽

2003 ◽

Vol 17 (27n28) ◽

pp. 1425-1435 ◽

Cited By ~ 4

Author(s):

Z. Z. GUO ◽

X. X. LIANG ◽

S. L. BAN

Keyword(s):

Binding Energy ◽

Ground State ◽

Pressure Effect ◽

Light Hole ◽

Binding Energies ◽

Wave Functions ◽

Type Ii ◽

Band Bending ◽

Effective Masses ◽

Transfer Method

A variational method is used to study the ground-state binding energies of interface light-hole excitons in ZnTe/CdSe type-II heterojunctions under the influence of hydrostatic pressure. The finite triangle potential well approximation is introduced considering the band bending near the interface. The asymptotic transfer method is adopted to obtain the sub-band energies and wave functions of the electrons and light holes. The pressure influence on the band offsets, the effective masses and the dielectric constant are considered in the calculation. The obvious pressure-induced increase of the exciton binding energy is demonstrated and the influences of the pressure-depended parameters on the binding energy are compared.

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Light- and Heavy-Hole Bound Exciton Transitions and Free to Bound Transitions in GaxAl1-xAs/GaAs Quantum Wells

MRS Proceedings ◽

10.1557/proc-163-313 ◽

1989 ◽

Vol 163 ◽

Author(s):

Donald C. Reynolds ◽

K.K. Bajaj

Keyword(s):

Quantum Wells ◽

Heavy Hole ◽

Free Exciton ◽

Light Hole ◽

Binding Energies ◽

Temperature Dependent ◽

Neutral Donor ◽

Free Hole ◽

Quantum Well Structures ◽

Exciton Transitions

AbstractExcitons bound to neutral donors in AlxGa1-xAs/GaAs quantum wells were observed by high resolution resonant excitation photoluminescence, and temperature dependent photoluminescence measurements. Changes in the binding energy of excitons are observed when the donors are located in the center of the well, at the edge of the well, or in the center of the barrier. The variations in these binding energies are reported as a function of well size from 75–350Å. The binding energies increased as the well size was reduced to about 100Å, with further reductions in well size they decreased.Light-hole free excitons bound to neutral donors were observed in AlxGa1-xAs/GaAs quantum wells. The transitions were observed, using selective excitation photoluminescence spectroscopy, in the energy region between the light-hole and heavy-hole free exciton transitions where no other intrinsic transitions exist. The neutral donor-bound heavy-hole free-exciton transitions were also observed when the light-hole bound exciton transitions were observed. Quantum well structures which showed no evidence of a heavy-hole donor bound exciton also showed no evidence of a light-hole donor bound exciton.Free to bound transitions, free hole to bound electron, have also been observed in the AlxGa1-xAs/GaAs quantum wells. The diamagnetic shift of these transitions was used to distinguish them from excitonic transitions.

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