Temperature dependence of the quantized states in aGaAs−Ga1−xAlx

Temperature dependence of excitonic transitions in AlxGa1−xAs/GaAs quantum wells

“…This is a strong experimental evidence of the influence of barrier height on the temperature dependence of excitonic transitions in QWs. These results contradict previous articles that concluded that the behavior of the temperature dependence of excitonic transitions in QWs and the band gap of GaAs are the same [12][13][14][15][16][17][18]30].…”

“…The temperature dependence of the excitonic transitions is attributed principally to electron-phonon interactions [9][10][11]. Results from AlGaAs/GaAs QWs show that the thermal shifts in exciton recombinations are in good agreement with the temperature shifts of bulk GaAs, the constituent material of the QW [12][13][14][15][16][17][18]. Kangarlu et al [12], using a photoreflectance technique and fitting experimental data with the Varshni model [19], concluded that the quantum confinement of electrons in Al x Ga 1−x As/GaAs QWs has no measured effect on the temperature behavior of the energy levels.…”

“…Results from AlGaAs/GaAs QWs show that the thermal shifts in exciton recombinations are in good agreement with the temperature shifts of bulk GaAs, the constituent material of the QW [12][13][14][15][16][17][18]. Kangarlu et al [12], using a photoreflectance technique and fitting experimental data with the Varshni model [19], concluded that the quantum confinement of electrons in Al x Ga 1−x As/GaAs QWs has no measured effect on the temperature behavior of the energy levels. Since the slope d E/dT = 0.4 meV K −1 of the bulk excitons in GaAs and two-dimensional excitons in QWs are similar at temperatures larger than 100 K, the phonon coupling in QWs are not different from the phonon coupling in bulk [15].…”

Temperature dependence of the lowest excitonic transition for an InAs ultrathin quantum well

“…Generally, it has been found that the temperature dependence of quantized energy levels follows the band gap variation of the relevant bulk constituent material in the well. 14,15 However, for ultrathin InAs/ GaAs QWs, Ksendzov et al 16 have shown that from 77 to 300 K the temperature dependence of the lowest energy transition for InAs/ GaAs QW follows neither the InAs nor GaAs band gap. On the other hand, according to Xu et al,17 when the InAs thickness is smaller than 1.7 ML the temperature dependence of the PL peak follows the InAs band gap very closely.…”

Temperature-dependent photoluminescence and contactless electroreflectance characterization of a ZnxCd1−xSe/Znx′Cdy′Mg1−x′−y′Se asymmetric coupled quantum well structure

“…Since the differences are within the probable errors of measurement, a detailed comparison of these parameters is difficult to perform. Therefore, as in the AlGaAs/GaAs heterostructure system [27], the main influence of temperature on the quantized transitions is attributed to the temperature dependence of the band Table 3 show that this relation is satisfied approximately. From Eq.…”