GaAs quantum well in the non-parabolic case: the effect of hydrostatic pressure on the intersubband absorption coefficient and the refractive index

Abstract

We investigated the effect of the hydrostatic pressure on the optoelectronic properties of a quantum well (QW) based on δ-doped GaAs sandwiched by Ga1-xAlxAs. We study the case of a non-parabolic conduction band where the aluminum content is set at 30%. We perform our calculations in the context of the approximation of the envelope function formalism using the finite difference method. Results show that the transition energies decrease with the increase of the hydrostatic pressure, which causes remarkable modifications on the optical properties of the QW nanostructure. The non-parabolicity effect is more important for small QW (Lw ≤ 5nm) and less marked in narrow and large QW. In addition, we study the absorption coefficient for 8 nm/4 nm/8 nm geometry. On the one hand, the pressure increase creates a displacement of the optical absorption coefficient towards low energies and a decrease of the absorption peak value. On the other hand, the refractive index moves towards higher energies. We show that in the presence of a hydrostatic pressure and following its effect on intersubband transitions, these optical properties also depend on the dopant concentration rate and the quantum well width. Our study finds interests for the nano-fabrication of quantum wells and in particular for those used in optical and electronic applications.

Exact Solutions for a Quantum Ring with a Dipolar Impurity

“…Regarding the se states, its presence increases the energy of the (n, 2) → (n, 1) transition by less than 0.04%. From 29, we see also that the corrections increase with the ratio m * /ε r and thus they are more pronounced for the compounds Ga 1−x Al x As, since the effective mass for these materials is given by the formula m * = (0.067 + 0.085x)m e with x real [55]. We show in Figs 5, 6 and 7, these changes for x = 0.3 used in [51,55] and also for the parameters of CdSe m * /ε r = 0.13/9.3 studied in [34].…”

“…From 29, we see also that the corrections increase with the ratio m * /ε r and thus they are more pronounced for the compounds Ga 1−x Al x As, since the effective mass for these materials is given by the formula m * = (0.067 + 0.085x)m e with x real [55]. We show in Figs 5, 6 and 7, these changes for x = 0.3 used in [51,55] and also for the parameters of CdSe m * /ε r = 0.13/9.3 studied in [34]. We observe that the dipole corrections are 2 times greater for the Ga 1−x Al x As than for the GaAs and they are 7 times more pronounced than the latter in the case of CdSe.…”

Advanced materials for energy harvesting, storage, sensing and environmental engineering

“…The present edition is a continuation of the three previous 2016, 2017 and 2018 editions [1][2][3]. It practically includes works on similar themes such as energy transfer and storage [4][5][6], materials for energy and photonics [7][8][9][10], solar thermal and photovoltaic [11,12]. The theme of sensors and the thermal and vibration energy harvesting using piezoelectric and pyroelectric effects received a particular attention [13][14][15].…”