Title




Electronic structure of a Si layer in a quantum barrier
 
Author




 
Abstract




We present a theoretical study of the electronic structure of a heavily Si deltadoped layer in a GaAs/AlxGa1xAs/GaAs quantum barrier. In this class of structures the effect of DX centers on the electronic properties can be tuned by changing the AlxGa1xAs barrier width and/or the Al concentration, which leads to a lowering of the DX level with respect to the Fermi energy without disturbing the wave functions much. A selfconsistent approach is developed in which the effective confinement potential and the Fermi energy of the system, the energies, the wave functions, and the electron densities of the discrete subbands have been obtained as a function of both the material parameters of the samples and the experimental conditions. The effect of DX centers on such structures at nonzero temperature and under an external pressure is investigated for three different models: (1) the DX(nc)(0) model with no correlation effects, (2) the d(+)/DX(0) model, and (3) the d(+)/DX() model with inclusion of correlation effects. In the actual calculation, influences of the background accepters, the discontinuity of the effective mass of the electrons at the interfaces of the different materials, band nonparabolicity, and the exchangecorrelation energy of the electrons have been taken into account. We have found that (1) introducing a quantum barrier into deltadoped GaAs makes it possible to control the energy gaps between different electronic; subbands; (2) the electron wave functions are mon spread out when the repellent effect of the barriers is increased as compared to those in deltadoped GaAs; (3) increasing the quantumbarrier height and/or the application of hydrostatic pressure are helpful to experimentally observe the effect of the DX centers through a decrease of the total freeelectron density; and (4) the correlation effects of the charged impurities are important for the systems under study. 
 
Language




English
 
Source (journal)




Physical review : B : condensed matter and materials physics.  Lancaster, Pa, 1998  2015
 




Physical Review B
 
Publication




Lancaster, Pa
:
1996
 
ISSN




10980121
[print]
1550235X
[online]
 
Volume/pages




54
:11
(1996)
, p. 79968004
 
ISI




A1996VL14500066
 
Full text (Publisher's DOI)




 
Full text (publisher's version  intranet only)




 
