Uncorrelated Excitonic Properties in Multilayered Cylindrical Quantum Dot

Abstract

The unbound exciton properties in multilayered cylindrical quantum dot (CQD) (core/shell/shell) have been studied theoretically, within the effective mass approximation and two-band model. The uncorrelated energy of an exciton confined in GaAs/Ga1-x1Alx1As/Ga1-x2Alx2As CQD as a function of the core and first shell radius is presented. The numerical results show that the quantum dot size and the confinement potentials depth significantly adjust the ground state uncorrelated energy of exciton. However, the exciton wave function parameters are dependent on the core and first shell radius (R1 and R2), as well as the concentration of the barrier’s materials.

Unbound Excitonic Properties in a Multilayered Quantum Dot under Hydrostatic Pressure and Temperature

“…5 shows the combined effects of pressure and temperature on the optical band gap energy in a CSSCQD. For a fixed pressure and temperature, we noticed that the band gap energy increases as the value of the core radius decreases and tends to a constant value for a large core radius (quantum well limit), which is consistent with the results obtained in wedge shaped QD [11][12][13][14][15]. Moreover, we notice that the band gap energy increases (see Figs.…”

“…In this work, we consider an unbound exciton (light hole and electron) confined in a GaAs core/shell/shell cylindrical quantum dot characterized by the core radius 𝑅𝑅 1 , the first shell radius 𝑅𝑅 2 and the height H. within the effective mass approximation and the two-band model, the Hamiltonian of the unbound electron-light hole system, under the effect of hydrostatic pressure and temperature, can be described as follows [14][15][16]:…”

“…The effect of temperature and pressure was taken into account in the effective mass approximation [13]. In our previous work, the effects of the confinement potentials of the first and second materials, the size of the core and the thickness of the first shell on the exciton (electron and hole) confinement with Columbic interaction in the core/shell/shell cylindrical QD (CSSCQD) have been studied [14,15]. To the best of our knowledge, there has been no theoretical report dealing with the effect of external hydrostatic pressure and temperature on the excitonic properties of CSSCQD.…”

The Effect of a Single Off-Center Shallow Donor Atom on the Binding Energy and Diamagnetic Susceptibility in a GaAs Horn Torus Quantum Dot

“…The interest in these structures is due to the fact that they could be realized in an experiment [18]. The presence of neutral and ionized donor impurities significantly improves optoelectronic properties under strong confinement conditions since their introduction reveals new energy levels in the band gap of semiconductors, which modify their optical and electronic properties [19][20]. Experiments have recently been performed to demonstrate the mechanism of dopant incorporation [21] as well as how the incorporations can be controlled [22].…”