Spatial Dependent Effective Mass for Donor Binding Energies in a Quantum Well in the Influence of an Electric Field

2009 ◽  
Vol 6 (1) ◽  
pp. 157-161 ◽  
Author(s):  
A. John Peter ◽  
L. Caroline Sugirtham
2012 ◽  
Vol 26 (06) ◽  
pp. 1250013 ◽  
Author(s):  
F. UNGAN ◽  
U. YESILGUL ◽  
E. KASAPOGLU ◽  
H. SARI ◽  
I. SOKMEN

The effects of nitrogen and indium mole concentration on the intersubband optical absorption for (1–2) transition and the binding energy of the shallow-donor impurities in a Ga 1-x In x N y As 1-y/ GaAs / Al 0.3 Ga 0.7 As quantum well under the electric field is theoretically calculated within the framework of the effective-mass approximation. Results are obtained for several concentrations of nitrogen and indium, and the applied electric field. The numerical results show that the intersubband transitions and the impurity binding energy strongly depend on the nitrogen and indium concentrations.


2006 ◽  
Vol 20 (24) ◽  
pp. 1529-1541 ◽  
Author(s):  
S. RAJASHABALA ◽  
K. NAVANEETHAKRISHNAN

The donor ionization energies in a quantum well and quantum dot with finite and infinite barriers are estimated for different well dimensions. Using the effective mass (EM) approximation, calculations are presented with constant effective mass and position dependent effective masses that are different for finite and infinite cases. Our results reduce to an approximate form used by X. H. Qi et al., Phys. Rev. B58 (1998) 10578 in the finite barrier model and that of L. E. Oliveira and L. M. Falicov, Phys. Rev. B34 (1986) 8676 in the infinite barrier case. Results are presented by taking the GaAs quantum well as an example. The use of constant effective mass of 0.067m0 is justified for well dimensions ≥a* where a* is an effective Bohr radius which is about 100 Å. While Qi et al. found a maximum of 22% variation in the binding energies due to mass variation, we obtained nearly 100% variation when mass variations are included correctly.


2006 ◽  
Vol 20 (21) ◽  
pp. 3049-3055 ◽  
Author(s):  
A. JOHN PETER

Polaronic shifts of the donor binding energies in an electric field in a quantum well are presented here. The properties of a polaron in a quantum well are investigated within the second-order perturbation theory. GaAs / Ga 1-x Al x As quantum well is chosen as an example to calculate the polaron energy. Since this system is a weak polar material, the electron-lattice coupling constant is small so this effect is considered by second-order perturbation theory. The polaronic effects are suppressed when an electric field is coupled. The diamagnetic susceptibility is also calculated and the results are compared with the results obtained using other approximation methods.


2018 ◽  
Vol 32 (04) ◽  
pp. 1850032 ◽  
Author(s):  
Monalisa Panda ◽  
Tapaswini Das ◽  
B. K. Panda

The electronic states in the laser-dressed hexagonal and cubic Al[Formula: see text]Ga[Formula: see text]N/GaN single quantum wells are calculated using the effective mass equation. The hexagonal single quantum well contains an internal electric field due to spontaneous and piezoelectric polarizations. The effective mass equation is solved by the finite difference method. The energy levels in both cubic and hexagonal laser-dressed wells are found to increase with increase in laser dressing as the effective well widths in both the wells increase. The intersubband energy spacing between first excited state and ground state increases in the cubic quantum well, whereas it decreases in the hexagonal well due to the presence of internal electric field in it. Using the compact density matrix method with iterative procedure, first-, second- and third-order nonlinear optical susceptibilities in the laser-dressed quantum well are calculated taking only two levels. While the susceptibilities in the hexagonal well are found to get red shifted, the susceptibilities in the cubic well are blue shifted.


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