Dependence of energy shifts on the field direction in a gradedGa1−xAl

Abstract

We report the energy shifts in an electric field in a Ga& Al"As graded-gap quantum well (GCJQW) and a novel method to calculate subbands. Our calculations have revealed the dependence of the energy shifts of subbands and excitons on the field direction in GGQW's. The subband dependence of energy shifts under an electric field in GGQW's is diff'erent from that in a square quantum well.

Diamagnetic susceptibility of a hydrogenic donor in a quantum dot

“…Q c is the conduction band offset [14] which is taken as 0.6, ∆E g (x) = 1.155 x + 0.37 x 2 is the bandgap difference [14] between GaAs well and Al x Ga 1-x As barrier and 'x' is the Al composition.We choose the trial wave function as [6] ( )…”

Subband and excitonic binding of graded GaAs/Ga1–xAlxAs quantum wells under an electric field

“…The effects of an external electric field on the optical properties of graded or square quantum wells (QWs) are the subject of extensive studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. This interest is partly due to the device possibilities in graded-gap structures such as sawtooth superlattices as first discussed by Coppaso et al [15].…”

“…The electronic structures of the graded-gap systems without an applied electric field have been studied by several authors [10,11]. There have been various studies on the effects of the external electric field applied along the growth axis-z on subband energies, carrier lifetimes [1][2][3], and exciton binding energies [18]. There are also some investigations on the corresponding superlattices [17,[19][20].…”

“…In their study of the properties of electrons and excitons in graded quantum wells of Ga 1−x Al x As in an electric field, Zhu et al [18] used a novel method of series expansion and took the electric field term as a perturbation.…”