1999 **Abstract:** Adopting a real-space tight-binding supercell approach, we i n vestigate interface roughness e ects in semiconductor heterostructures. AlAs GaAs AlAs 001 QWs of average width W are considered, in which one of the interfaces is planar and the other has a shape de ned by periodic steps with amplitude A and wavelength . The oscillator strength f of the fundamental transition in the well describes the optical nature of the heterostructures. By investigating the wavefunctions as a function of the interface paramete…

Help me understand this report

Search citation statements

Paper Sections

Select...

2

Citation Types

0

2

0

Year Published

2014

2014

Publication Types

Select...

1

Relationship

0

1

Authors

Journals

(2 citation statements)

(1 reference statement)

0

2

0

“…10. For the Al and Ga atoms in an alloy, the values of their on-site energies were set equal to the same average, which implies that the atoms partially lost their individuality and become a pseudo atom with orbital energies between the former values, in a similar fashion to the Virtual Crystal Approximation (VCA) [11]. However, only the on-site energies were varied: the zetas and the expansion coefficients were kept at their original values given in the Table I. Random alloys, as were considered in this article, lack formal translational symmetry and thus k is not a good quantum number, leading an inadequacy of the language of bandstructure dispersion E(k) to describe the energy states of the alloys.…”

confidence: 99%

“…10. For the Al and Ga atoms in an alloy, the values of their on-site energies were set equal to the same average, which implies that the atoms partially lost their individuality and become a pseudo atom with orbital energies between the former values, in a similar fashion to the Virtual Crystal Approximation (VCA) [11]. However, only the on-site energies were varied: the zetas and the expansion coefficients were kept at their original values given in the Table I. Random alloys, as were considered in this article, lack formal translational symmetry and thus k is not a good quantum number, leading an inadequacy of the language of bandstructure dispersion E(k) to describe the energy states of the alloys.…”

confidence: 99%

“…However, only the on-site energies were varied: the zetas and the expansion coefficients were kept at their original values given in the Table I. Random alloys, as were considered in this article, lack formal translational symmetry and thus k is not a good quantum number, leading an inadequacy of the language of bandstructure dispersion E(k) to describe the energy states of the alloys. Nevertheless, several theoretical approaches have been proposed in the literature [11][12][13][14][15][16], intending to restore the relation between the energy and k. The Virtual Crystal Approximation [11] (VCA) was one of the first approximation employed in the theoretical study of A x B 1−x C semiconductor alloys into the TB frame, where the A and B atoms are replaced by a fictitious atom, whose TB parameters are calculated as weighted averages of the AC and BC binary parameter values. More realistic approaches, where the atom identity is preserved, are based on the spectral decomposition of the alloys eigenstates [13,14] or the unfolding of the supercell Brillouin zone [12,15,16]: the former approach employing plane waves as basis set and the second localized orbitals.…”

confidence: 99%