Effects of width of the quantum well on the shift in transition energy with operating current in In<inf>x</inf>Ga<inf>1−x</inf>N/GaN quantum well diodes

The effects of the electron–phonon interaction on the electron (or hole) energy levels in parabolic quantum well (PQW) structures are studied. The ground state, the first excited state and the transition energy of the electron (or hole) in the GaAs/Al 0.3 Ga 0.7 As parabolic quantum well are calculated by using a modified Lee–Low–Pines Variational method. The numerical results are given and discussed. A comparison between the theoretical and experimental results is made.

Download Full-text

Interband optical transition energy and oscillator strength in a lead based CdSe quantum dot quantum well heterostructure

10.1063/1.4918110 ◽

2015 ◽

Author(s):

S. N. Saravanamoorthy ◽

A. John Peter

Keyword(s):

Quantum Dot ◽

Quantum Well ◽

Oscillator Strength ◽

Transition Energy ◽

Optical Transition ◽

Optical Transition Energy ◽

Interband Optical Transition ◽

Cdse Quantum Dot

Download Full-text

BINDING ENERGY OF A BOUND POLARON IN THE FINITE PARABOLIC QUANTUM WELL

Modern Physics Letters B ◽

10.1142/s0217984901002026 ◽

2001 ◽

Vol 15 (20) ◽

pp. 827-835 ◽

Cited By ~ 5

Author(s):

FENG-QI ZHAO ◽

XI XIA LIANG

Keyword(s):

Binding Energy ◽

Quantum Well ◽

Ground State Energy ◽

Ground State ◽

State Energy ◽

Transition Energy ◽

Energy Levels ◽

Phonon Interaction ◽

Electron Phonon Interaction ◽

Bound Polaron

We have studied the effect of the electron–phonon interaction on the energy levels of the bound polaron and calculated the ground-state energy, the binding energy of the ground state, and the 1 s → 2 p ± transition energy in the GaAs/Al x Ga 1-x As parabolic quantum well (PQW) structure by using a modified Lee–Low–Pines (LLP) variational method. The numerical results are given and discussed. It is found that the contribution of electron–phonon interaction to the ground-state energy and the binding energy is obvious, especially in large well-width PQWs. The electron–phonon interaction should not be neglected.

Download Full-text

Free polaron energy levels in AlyGa1−yN/AlxGa1−xN triangle quantum well structures

Modern Physics Letters B ◽

10.1142/s0217984917501871 ◽

2017 ◽

Vol 31 (17) ◽

pp. 1750187 ◽

Cited By ~ 2

Author(s):

Hong Yu Pan ◽

Feng Qi Zhao

Keyword(s):

Quantum Well ◽

Optical Phonon ◽

Transition Energy ◽

Energy Transition ◽

Electron Effective Mass ◽

Total Contribution ◽

Quantum Well Structures ◽

Quantum Well Structure ◽

Composition Formula ◽

Polaron Energy

In this work, a variational method is used to examine the problems relevant to the free polaron energy spectrum in a wurtzite Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangle quantum well structure. The numerical calculations for the ground state energy, transition energy and polaron energy shifts as the functions of well-width [Formula: see text] and composition [Formula: see text] are carried out by considering the anisotropies of the parameters, such as the optical phonon frequency, dielectric constant and electron effective mass, as well as their observed changes with coordinate [Formula: see text] in this system. The research results show that the polaron energy shift caused by the electron–optical phonon interaction is large, and leads to an obvious energy decrease in the Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangular quantum well structure. The contribution of the confined phonon is found to increase with the increasing of the well-width and composition [Formula: see text], while that of the half space phonon is observed to decrease with the increasing of the well-width and composition [Formula: see text]. The total contribution of the phonon increases with the increasing composition [Formula: see text], while a minimum is found to occur to the total contribution of the phonon during the decreasing process with the well-width. As the [Formula: see text] increases, the free polaron energies and transition energies decrease. Meanwhile, with the increasing of the composition [Formula: see text], the energy and transition energy are found to be increased. In the Al[Formula: see text]Ga[Formula: see text]N/Al[Formula: see text]Ga[Formula: see text]N triangular quantum well structure, the trends of the free polaron energy, transition energy and polaron energy shifts with the well-width and composition [Formula: see text] are found to be similar to those in the GaN/Al[Formula: see text]Ga[Formula: see text]N square quantum well structure. However, the corresponding values in the triangular quantum well structure are obviously greater than those in the square quantum well structure.

Download Full-text

Polaronic Effects in Wurtzite InxGa1-xN/GaN Parabolic Quantum Well

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.145 ◽

2012 ◽

Vol 629 ◽

pp. 145-151

Author(s):

Ren Tu Ya Wu ◽

Qi Zhao Feng

Keyword(s):

Quantum Well ◽

Ground State Energy ◽

Optical Phonon ◽

Ground State ◽

State Energy ◽

Transition Energy ◽

Energy Levels ◽

Phonon Modes ◽

Phonon Interaction ◽

Zinc Blende

The energy levels of polaron in a wurtzite InxGa1-xN/GaN parabolic quantum well are investigated by adopting a modified Lee-Low-Pines variational method. The ground state energy, the transition energy and the contributions of different branches of optical phonon modes to the ground state energy as functions of the well width are given. The effects of the anisotropy of optical phonon modes and the spatial dependence effective mass, dielectric constant, phonon frequency on energy levels are considered in calculation. In order to compare, the corresponding results in zinc-blende parabolic quantum well are given. The results indicate that the contributions of the electron-optical phonon interaction to ground state energy of polaron in InxGa1-xN/GaN is very large, and make the energy of polaron reduces. For a narrower quantum well，the contributions of half-space optical phonon modes is large , while for a wider one, the contributions of the confined optical phonon modes are larger. The ground state energy and the transition energy of polaron in wurtzite InxGa1-xN/GaN are smaller than that of zinc-blende InxGa1-xN/GaN, and the contributions of the electron-optical phonon interaction to ground state energy of polaron in wurtzite InxGa1-xN/GaN are greater than that of zinc-blende InxGa1-xN/GaN. The contributions of the electron-optical phonon interaction to ground state energy of polaron in wurtzite InxGa1-xN/GaN (about from 22 to 32 meV) are greater than that of GaAs/AlxGa1-xAs parabolic quantum well (about from 1.8 to 3.2 meV). Therefore, the electron-optical phonon interaction should be considered for studying electron state in InxGa1-xN/GaN parabolic quantum well.

Download Full-text