Effect of quantum well width on the electron and hole states in different single quantum well structures

Abstract

In this study the electron and hole states in Al0.33Ga0.67As/GaAs single quantum well structures including squared QW, step QW and tilted QW, have been theoretically studied by solving the Schrodinger equation in real space. The energies and wave functions of electron and hole are calculated for different well widths. It is found that energy level of electron and hole decreases with increasing the well width. Adding step or tilted layers gives rise to the decrease of electron and hole energy levels. The ground state energy level in a tilted single quantum well structure is lower than that in a step single quantum well structure. It is also found that the energy of electron and hole ground states do not change as the width of step layer increase. This is because the ground state occupies in a lower well only. The wave functions are symmetric (ground state) and antisymmetric (the first excited state). The maximum of ground state wave function is at the central of the well and the probability of finding electron and hole in excited states are different in each region. The hole levels are lower than the electron levels due to the lower well depth and higher mass of hole compared to electron.

Efficient Single-Photon Sources Based on Chlorine-Doped ZnSe Nanopillars with Growth Controlled Emission Energy

“…A pronounced redshift of the emission energy with increasing the QW width is observed. We attribute this redshift to the change of the QW confinement, also altering the exciton binding energy as a function of the QW width . Moreover, as can be seen in Figure b, shrinking the QW width from 4.7 to 2.7 nm increases the emission energy of the D 0 X peak by 30 meV.…”

“…We attribute this redshift to the change of the QW confinement, also altering the exciton binding energy as a function of the QW width. 29 Moreover, as can be seen in Figure 3b, shrinking the QW width from 4.7 to 2.7 nm increases the emission energy of the D 0 X peak by 30 meV. This wide tuning range reveals the enormous effect of QW confinement on bound-exciton-related emission allowing us to precisely engineer and fabricate single-photon emitters with practically predefined emission properties.…”