DONOR AND ACCEPTOR STATES IN GaAs-(Ga, Al)As QUANTUM DOTS: EFFECTS OF HYDROSTATIC PRESSURE AND AN INTENSE LASER

2010 ◽  
Vol 24 (29) ◽  
pp. 5761-5770 ◽  
Author(s):  
A. MIGUEZ ◽  
R. FRANCO ◽  
J. SILVA-VALENCIA
Keyword(s):  
Quantum Dots ◽  
Hydrostatic Pressure ◽  
Binding Energy ◽  
Laser Field ◽  
Binding Energies ◽  
Field Amplitude ◽  
Pressure Effects ◽  
Intense Laser ◽  
Mass Approximation ◽  
Donor And Acceptor

We calculated the binding energies of shallow donors and acceptors in a spherical GaAs - Ga 1-x Al x As quantum dot under the combined effect of isotropic hydrostatic pressure and an intense laser. We used a variational approach within the effective mass approximation. The binding energy was computed as a function of hydrostatic pressure, dot sizes and laser field amplitude. The results showed that the impurity binding energy increases with pressure and decreases with the laser field amplitude when other parameters are fixed. We also found that the pressure effects are more dramatic for donor than acceptor impurities, especially for quantum dots with small radii.

scholarly journals Barrier Thickness and Hydrostatic Pressure Effects on Hydrogenic Impurity States in Wurtzite GaN/AlxGa1−xN Strained Quantum Dots

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Guangxin Wang ◽  
Xiuzhi Duan ◽  
Wei Chen
Keyword(s):  
Quantum Dots ◽  
Hydrostatic Pressure ◽  
Binding Energy ◽  
Effective Mass ◽  
Dielectric Constants ◽  
Pressure Effects ◽  
Physical Parameters ◽  
Barrier Thickness ◽  
Hydrogenic Impurity ◽  
Donor Binding Energy

Within the framework of the effective mass approximation, barrier thickness and hydrostatic pressure effects on the ground-state binding energy of hydrogenic impurity are investigated in wurtzite (WZ) GaN/AlxGa1−xN strained quantum dots (QDs) by means of a variational approach. The hydrostatic pressure dependence of physical parameters such as electron effective mass, energy band gaps, lattice constants, and dielectric constants is considered in the calculations. Numerical results show that the donor binding energy for any impurity position increases when the hydrostatic pressure increases. The donor binding energy for the impurity located at the central of the QD increases firstly and then begins to drop quickly with the decrease of QD radius (height) in strong built-in electric fields. Moreover, the influence of barrier thickness along the QD growth direction and Al concentration on donor binding energy is also investigated. In addition, we also found that impurity positions have great influence on the donor binding energy.

BINDING ENERGY OF ACCEPTORS IN SEMIMAGNETIC QUANTUM DOTS

2006 ◽  
Vol 05 (01) ◽  
pp. 173-181 ◽  
Author(s):  
A. JOHN PETER
Keyword(s):  
Quantum Dots ◽  
Binding Energy ◽  
Bound States ◽  
Mean Field Theory ◽  
Mean Field ◽  
Binding Energies ◽  
Mass Approximation ◽  
Variational Calculations ◽  
Shallow Acceptors ◽  
Peak Value

The binding energies of shallow acceptors in Cd 1-x in Mn x in Te/ Cd 1-x out Mn x out Te quantum dots are calculated in the presence of external magnetic fields. Variational calculations are performed within effective mass approximation. The results show that the impurity binding energy (i) increases with the reduction in dot sizes, (ii) decreases with the magnetic field is increased for a given dot, and (iii) reaches a peak value as the dot radius decreases and then diminishes to a limiting value corresponding to the radius for which there are no bound states in the quantum dot. Spin polaronic shifts are estimated with the acceptor envelope function using a mean field theory. These results are compared with the existing literatures.

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