Neutral and charged donor in a 3D quantum dot

Physica Status Solidi (b)

2009

The linear and the third‐order nonlinear optical absorption spectra of a donor impurity confined by a quantum ring are studied using the matrix diagonalization method within the effective‐mass approximation. The linear and the third‐order nonlinear optical absorption coefficients between the ground (L = 0) and the first excited state (L = 1) have been examined based on the computed energies and wavefunctions. The results are presented as a function of the incident photon energy for the different values of the confinement strength, the incident optical density and the ring radius. We found the confinement strength, the incident optical density and the ring radius have a great effect on the linear, the third‐order nonlinear and total absorption spectra. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Section: Original Papersupporting

confidence: 51%

Absorption spectra of a donor impurity in a quantum ring

Physica Status Solidi (b)

2009

“…On the other hand, impurities in semiconductors influence both transport and optical properties so that topics like confined D -centers in low-dimensional space have been extensively investigated. Since the existence of the D -centers in center-doped GaAs/Al x Ga 1-x As multiple quantum wells (QWs) was first reported by Huant et al [3] in 1990, the D -centers in semiconductor nanostructures have been investigated from the experimental [4][5][6] and theoretical [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] points of view.…”

Section: Introduction the Dmentioning

confidence: 99%

Investigation of D^– centers confined by spherical quantum dots

Physica Status Solidi (b)

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)

“…We know that, in the presence of magnetic field, the D − centers in QDs have more than one bound states. [21,25,28,29] In conclusion, we have applied the spherical parabolic confining potential to a description of the D − centers in semiconductor QDs. We have calculated the energy levels of L = 0 (S states) for the even parity and L = 1 (P states) for the odd parity as functions of the confined potential radius.…”

Section: Resultsmentioning

confidence: 99%

A Negative Donor Center Trapped by a Spherical Quantum Dot

2008

Commun. Theor. Phys.

The properties of the low-lying states of a negative donor center trapped by a spherical quantum dot, which is subjected to a parabolic potential confinement, are investigated in the absence of magnetic field. The calculations have been performed by means of the exact diagonalization of the Hamiltonian matrix within the effective-mass approximation. We find that there is only one bound state the D− center in a spherical parabolic quantum dot in the absence of magnetic field. The binding energy of the ground state is obtained as a function of the dot size. Moreover, the critical confined potential radius value at which the negative donor center changes from unbound to bound is obtained.