Concentration Dependences of the Electron Effective Mass, Fermi Energy, and Filling of Subbands in Doped InAs/AlSb Quantum Wells

Abstract

Results of researches concerning the properties of the two-dimensional (2D) degenerate electron gas in a single quantum well on the basis of the InAs/AlSb heterostructure are reported. The non-parabolic character of the InAs and AlSb conduction bands is described by a simplified Kane model. The dispersion curves for first three subbands are calculated, as well as the dependences of the Fermi energy, subband filling, and effective mass of electrons at the Fermi level on the total 2D electron concentration. The obtained results are in good agreement with experimental data.

Energy Levels in Nanowires and Nanorods with a Finite Potential Well

“…To take into account the nonparabolicity of the zone, we use the Kane model [9]. Various approximations for the effective mass are given in [10,[40][41][42][43]; we will use the following expression for the effective mass:…”

The Density of States of the Two Dimensional Electron Gas in InAs/AlSb Quantum Well

“…It is necessary will note, that the formula (5) is correct under condition, when ( ) c F m E independent on the number of subbands i, strictly speaking. This condition is well carried out for InAs/AlSb QW [5,11].…”

“…From investigations [5,[8][9][10][11] follows, that in the QW hetero structure based on narrow-gap semiconductors as the InAs/AlSb or InAsSb/AlSb transport effective mass of an electron in the QW ( ) c F m E strongly depends Fermi energy, however, on the Fermi level, it is weakly dependent on the number of subband i. Only under this condition, formula (4) can be written as…”

“…It can be shown [11] that, for dispersion (10) the total 2D electron concentrations s n can be written as ( )…”

“…The system of equations (12) and (13) allows finding the DOS depending from the total concentration ( ) s s n ρ , and the system of equations (11) and (13) allows finding the depending of effective mass at the Fermi level from the concentration ( ) c s m n . In the limit gA E → ∞ from the relations (11), (12) and (13) follows a formula for the parabolic bands.…”