Donor binding energies and spin–orbit coupling in a spherical quantum dot

In this article, the binding energy of a hydrogenic donor impurity in weakly oblate Ellipsoidal Quantum Dot (EQD), using the perturbation theory within the framework of effective mass approximation, is investigated. In this regard, the binding energies of 1S, 2S and 2P 0 states for GaAs/Al x Ga 1-x As structures, as functions of the dot radius and ellipticity constant, are calculated. Results show that variations of binding energies of a hydrogenic impurity with respect to the dot dimension are similar to the case of Spherical Quantum Dot (SQD). In addition, it is found that the binding energy is inversely proportional to the ellipticity constant. This behavior is more profound for 2P 0 state, where, depending on the dot's dimensionality and ellipticity, the binding energy may become negative.

“…, at some radii is negative, which shows that 0 2P state is unbounded at these radii. This behavior is in good agreement with those reported in [11].…”

Section: Original Papersupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Binding energy of a hydrogenic donor impurity in an ellipsoidal finite‐potential quantum dot

Barati

Rezaei

Vahdani

2007

“…l = 0$)) and excited state(

1 p \left(\right. l = 1 \left.\right)

) of the SQD system, respectively, are given by [ 14,41,47 ]

$$\psi_{1 s}^{\text{imp}} \left(\right. r , r_{i} \left.\right) = \left{\right.

…”

Section: Theorymentioning

confidence: 99%

“…The conduction band offset parameters are taken as Q c ¼ 0.6 for QD1 and QD2, Q c ¼ 0.5 for QD3, and Q c ¼ 0.3 for QD4 and x = 0.35 is fixed for four different structures. [20,[49][50][51][52][53] In the presence of impurities, the trial wave functions for the ground (1sðl ¼ 0)) and excited state(1pðl ¼ 1Þ) of the SQD system, respectively, are given by [14,41,47]…”

Section: Theorymentioning

confidence: 99%

“…In recent years, the investigation of the physical and optical properties of quantum wells (QWWs), wires (QWs), and dots (QDs) made of different materials has been of great importance in heterostructures, and many theoretical and experimental studies have been carried out for these structures. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In particular, QDs based on GaAs/GaAlAs (QD1), InAs/InGaAs (QD2), InAs/InAlAs (QD3), and InP/InGaP (QD4), which are composed of semiconductor materials, are widely used in various application areas, especially in microelectronic and optoelectronic devices. [15][16][17][18][19][20] Also, impurities play an important role in understanding the optical and electronic properties of such structures.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Calculation of Intradonor Normalized Transition Energy in Spherical Quantum Dots Made of Different Materials

Mese

Cicek

Özkapı

et al. 2023

Under the effective mass approximation, the binding energies, transition energies between 1s and 1p states, and normalized transition energies of spherical quantum dots made of different materials are calculated using the variational method. In particular, binding, transition, and normalized transition energies are examined depending on the radius of the quantum dot and the position of the hydrogenic impurity. It is observed that the binding energy and transition energy decrease as the radius of the quantum dot increases, whereas the normalized transition energy increases. In all four different structures, it is seen that the binding energy first reaches a maximum and then starts to decrease according to the position of the hydrogenic impurity. In contrast, the transition energy behaves almost the opposite. Additionally, when the change of the normalized transition energy is examined according to the impurity position, it is determined that it decreases up to the value of ri/R = 0.6 and then remains almost constant. According to our literature review, the normalized transition energy for the four different quantum dots is calculated for the first time in this study.

Investigation of D^– centers confined by spherical quantum dots

Xie

2008

A negative donor center D– in a spherical Gaussian potential quantum dot is studied. The calculations have been performed by means of the exact diagonalization of the Hamiltonian matrix within the effective‐mass approximation. The dot‐radius and confinement‐height dependences of the binding energies of the D– center are obtained. We find that the stability of the D– center strongly depends on the dot radius and the depth of the confining potential. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)