Abstract In this paper we theoretically investigate the role of hydrostatic pressure by analyzing its influence on potential barrier’s height in GaAs/Al x Ga 1 − x As core/shell spherical quantum dots. The values of hydrostatic pressure considered here are always below the Γ − X crossover. In addition, we take into account the barrier shell’s size effects and the barrier’s aluminum concentration, looking for a description of the features of the intraband optical absorption coefficient in the system. The electronic structure is calculated within the effective mass approximation. From the numerical point of view the hybrid matrix method was implemented to avoid numerical instability issues that appears in the conventional transfer matrix method. The main intersubband optical transition is considered to take place between the 1 s and 1 p computed electronic states. The results show that the absorption coefficient undergoes first a red-shift and later a more pronounced blue-shift, depending on the Al x Ga 1 − x As barrier width ( w b 1 ). The absorption coefficient experiences a blue-shift as the barrier’s aluminum concentration increases, and it is non monotonically red-shifted as the hydrostatic pressure augments, due to the barrier’s height pressure dependency. For the chosen system parameters, the absorption coefficient resonant peak lies within the range of 20 to 30 meV, that corresponds to the THz frequency region. Accordingly, this system can be proposed as a building block for photodetectors in the THz electromagnetic spectrum region.

中文翻译：

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静水压力和壳的铝成分对核/壳球形 GaAs/AlxGa1−xAs 量子点带内吸收系数的影响

摘要 在本文中，我们通过分析静水压力对GaAs/Al x Ga 1 - x As 核/壳球形量子点势垒高度的影响，从理论上研究了静水压力的作用。此处考虑的静水压力值始终低于 Γ - X 交叉点。此外，我们考虑了势垒壳的尺寸效应和势垒的铝浓度，寻找系统中带内光吸收系数特征的描述。在有效质量近似值内计算电子结构。从数值的角度来看，混合矩阵方法的实施是为了避免传统传递矩阵方法中出现的数值不稳定问题。主要的子带间光学跃迁被认为发生在 1 s 和 1 p 计算电子状态之间。结果表明，吸收系数首先发生红移，然后发生更明显的蓝移，这取决于 Al x Ga 1 - x As 势垒宽度 ( wb 1 )。随着屏障的铝浓度增加，吸收系数发生蓝移，并且由于屏障的高度压力依赖性，随着静水压力的增加，吸收系数发生非单调红移。对于所选的系统参数，吸收系数共振峰位于 20 到 30 meV 的范围内，对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。结果表明，吸收系数首先发生红移，然后发生更明显的蓝移，这取决于 Al x Ga 1 - x As 势垒宽度 ( wb 1 )。随着屏障的铝浓度增加，吸收系数发生蓝移，并且由于屏障的高度压力依赖性，随着静水压力的增加，吸收系数发生非单调红移。对于选定的系统参数，吸收系数共振峰位于 20 到 30 meV 的范围内，对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。结果表明，吸收系数首先发生红移，然后发生更明显的蓝移，这取决于 Al x Ga 1 - x As 势垒宽度 ( wb 1 )。随着屏障的铝浓度增加，吸收系数发生蓝移，并且由于屏障的高度压力依赖性，随着静水压力的增加，吸收系数发生非单调红移。对于所选的系统参数，吸收系数共振峰位于 20 到 30 meV 的范围内，对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。随着屏障的铝浓度增加，吸收系数发生蓝移，并且由于屏障的高度压力依赖性，随着静水压力的增加，吸收系数发生非单调红移。对于所选的系统参数，吸收系数共振峰位于 20 到 30 meV 的范围内，对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。随着屏障的铝浓度增加，吸收系数发生蓝移，并且由于屏障的高度压力依赖性，随着静水压力的增加，吸收系数发生非单调红移。对于所选的系统参数，吸收系数共振峰位于 20 到 30 meV 的范围内，对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。对应于太赫兹频率区域。因此，该系统可以被提议作为太赫兹电磁频谱区域中光电探测器的构建模块。