scholarly journals Tilted electric-field and hydrostatic pressure effects on donor impurity states in cylindrical GaAs quantum disks

2008 ◽  
Vol 40 (5) ◽  
pp. 1383-1385 ◽  
Author(s):  
S.Y. López ◽  
N. Porras-Montenegro ◽  
E. Tangarife ◽  
C.A. Duque
Keyword(s):  
Hydrostatic Pressure ◽  
Electric Field ◽  
Pressure Effects ◽  
Donor Impurity ◽  
Impurity States ◽  
Quantum Disks

Influence of Al Composition on Donor Impurity States in Self-Formed GaAs-AlxGa1-xAs Quantum Rings

2013 ◽  
Vol 380-384 ◽  
pp. 4284-4289
Author(s):  
Guang Xin Wang ◽  
Xiu Zhi Duan
Keyword(s):  
Binding Energy ◽  
Electric Field ◽  
Growth Direction ◽  
Uniform Electric Field ◽  
Donor Impurity ◽  
Impurity States ◽  
Quantum Rings ◽  
Mass Approximation ◽  
Donor Binding Energy ◽  
Special Value

Based on the the effective mass approximation and variational approach, the donor impurity states confined in self-formed GaAs/AlxGa1-xAs quantum rings (QRs) are investigated theoretically. A uniform electric field is applied along the growth direction of the QR. The different effective masses in the different regions of the GaAs/AlxGa1-xAs QR are taken into consideration. Numerical results show that the binding energy of a donor impurity increases gradually, reaches a maximum value, and then decreases quickly to the special value as the QR height decreases. Given a fixed QR size, the binding energy increases for the impurity located at the center of the QR when the Al composition increases. In addition, it can also be found that when the applied electric field strength increases, the donor binding energy increases for impurities localized at the negative z axis of the QR; however, the donor binding energy decreases slightly for impurities located at the center and positive z axis of the QR.

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