We investigated the feasibility of directly estimating split-off hole effective mass m _so from Franz–Keldysh oscillations using non-destructive and non-invasive photoreflectance spectroscopy. We used an undoped/n-type GaAs epitaxial structure and two GaAs p–i–n diode structures. We observed the phenomenon that Franz–Keldysh oscillations, which originate both the E ₀ fundamental transition and from the E ₀ + Δ_so transition energy, appear in the photoreflectance spectra at room temperature. Initially, from the electro-optic constant ℏΘ _HH of the Franz–Keldysh oscillations originating from the E ₀ fundamental transition, we deduced the built-in electric field F in each sample with the use of the relation ℏΘ _HH = (e ²ℏ² F ²/2μ _HH)^1/3, where the quantity μ _HH is the reduced effective mass of the electron and heavy hole. In the next step, we calculated the reduced effective mass μ _so of the electron and split-off hole using the relation ℏΘ _so = (e ²ℏ² F ²/2μ _so)^1/3, where the quantity ℏΘ _so is the electro-optic constant of the Franz–Kelysh oscilations from the E ₀ + Δ_so transition. Finally, we estimated the split-off hole effective mass m _so from the reduced effective mass μ _so. The estimated split-off hole effective mass agrees with the reported value obtained experimentally. Thus, we conclude that the split-off hole effective mass is estimatable from analyzing the Franz–Keldysh oscillations in the photoreflectance spectra. We also compare the present hole effective masses to those theoretically known and discuss the appropriateness of the electronic-band calculations.

我们研究了使用非破坏性和非侵入性光反射光谱从 Franz-Keldysh 振荡直接估计分裂孔有效质量m _so的可行性。我们使用了一个未掺杂/ n型 GaAs 外延结构和两个 GaAs p – i – n二极管结构。我们观察到这种现象，即源自E ₀基本跃迁和E ₀ + Δ _so跃迁能量的Franz-Keldysh 振荡出现在室温下的光反射光谱中。最初，由电光常数 ℏ Θ _HH在源自E ₀基本跃迁的 Franz-Keldysh 振荡中，我们使用关系式 ℏ Θ _HH = ( e ² ℏ ² F ² /2 μ _HH ) ^1/推导出每个样品中的内建电场F ³，其中数量μ _HH是电子和重空穴的减少的有效质量。在下一步骤中，我们计算了降低有效质量μ_这样的电子和拆过孔采用ℏ关系Θ_所以=（ë ² ℏ ² F ² /2 μ _so ) ^1/3，其中量 ℏ Θ _so是来自E ₀ + Δ _so跃迁的 Franz-Kelysh 振荡的电光常数。最后，我们估计分割出来的空穴有效质量米 _所以从减小的有效质量μ _所以. 估计的分裂孔有效质量与实验获得的报告值一致。因此，我们得出结论，通过分析光反射光谱中的 Franz-Keldysh 振荡，可以估计分裂孔的有效质量。我们还将目前的孔有效质量与理论上已知的质量进行了比较，并讨论了电子能带计算的适当性。