Uniaxial stress dependence of spatially confined excitons

Electroluminescence in quantum well heterostructures p‐AlxGa1–xAs/GaAs1–yPy/n‐AlxGa1–xAs under uniaxial stress

“…As well as it also takes place under hydrostatic pressure [5,6], the blue shift of the EL wavelength is attributed to an increase of the effective energy gap in the initially tensile strained GaAs 1-y P y QW. Please see the following values for comparison of our recent results with previously published data in the literature: The energy shift of light hole excitons under uniaxial stress along [100] direction in GaAs/Al 0.3 Ga 0.7 As QWs is about 5.5 meV/kbar [1] and it is about 5 meV/kbar under stress in [110] direction in GaAs/Al 0.5 Ga 0.5 As QWs [2], while in laser diodes under hydrostatic pressure the observed energy shifts are in the range of 8 meV/kbar to 10.5 meV/kbar [5]. By the way, our results in [110] direction go along with the effect of packaging-induced strain on indium soldered diode laser bars mounted on Cu heat sinks [14].…”

“…Since the first experimental investigations of an in-plane uniaxial stress influence on the characteristic transition energies of heavy-and light-hole excitons confined in GaAs/Al x Ga 1-x As quantum wells [1,2] had been reported, the modification of optical and transport properties under uniaxial stress and hydrostatic pressure was extensively studied in III-V semiconductor compounds (see e.g. Ref.…”

Analytic solutions for the valence subband mixing at the zone center of a GaAs/AlxGa1<

“…A great advantage of uniaxial stress as opposed to built-in strain is its ability to tune 26 the valence band structure to different strains at which strong observable features are expected theoretically, and hence to optimize certain electronic or optical properties of the quantum well. By applying in-plane uniaxial stress along the ͓100͔ direction in III-V structures grown along the ͓001͔ direction it is furthermore possible to couple the well-defined zone-center valence states 23,24,28,[30][31][32] in contrast to the case of built-in strain, where they do not couple. 31 Since, however, most experiments probe exciton effects near the zone center, i.e., close to zero in-plane wave vector k ʈ , these stress-induced mixing effects are expected to be observable in experiments.…”

“…22 One way of generating anisotropic strain is to grow layered structures with built-in strain; this has been investigated intensively over the last 15 years. 18 Comparatively little attention, either experimentally [23][24][25][26][27][28] or theoretically, 24,[29][30][31][32][33] has been given to the alternative possibility of inducing anisotropic strain using an external uniaxial stress. A great advantage of uniaxial stress as opposed to built-in strain is its ability to tune 26 the valence band structure to different strains at which strong observable features are expected theoretically, and hence to optimize certain electronic or optical properties of the quantum well.…”

Electron spin orientation under in-plane optical excitation in GaAs quantum wells

“…We expect that this result was caused by the position-dependent inhomogeneous strain that was unintentionally present in the sample during the low-temperature experiments, thus resulting in a small shift of the resonance energies. 24 The sample was glued to a sample holder such that the edge used for the in-plane excitation was free-standing. Thus upon cooldown the edge might have experienced a different strain compared to the rest of the sample.…”