Mid-infrared optical Hall effect measurements are used to determine the free charge carrier parameters of an unintentionally doped wurtzite-structure $c$-plane oriented In$_{0.33}$Ga$_{0.67}$N epitaxial layer. Room temperature electron effective mass parameters of $m^{*}_{\bot}=(0.205 \pm 0.013)~m_0$ and $m^{*}_{\parallel}=(0.204 \pm 0.016)~m_0$ for polarization perpendicular and parallel to the $c$-axis, respectively, were determined. The free electron concentration was obtained as $(1.7 \pm 0.2)\times 10^{19}~$cm$^{-3}$. Within our uncertainty limits we detect no anisotropy for the electron effective mass parameter and we estimate the upper limit of the possible effective mass anisotropy is 7$\%$. We discuss the influence of band nonparabolicity on the electron effective mass parameter as a function of In content. The effective mass parameter is consistent with a linear interpolation scheme between the conduction band mass parameters in GaN and InN when the strong nonparabolicity in InN is included. The In$_{0.33}$Ga$_{0.67}$N electron mobility parameters were found to be anisotropic supporting previous experimental findings for wurtzite-structure GaN, InN, and Al$_{x}$Ga$_{1-x}$N epitaxial layers with $c$-plane growth orientation.

中文翻译：

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由中红外光学霍尔效应确定的 In0.33Ga0.67N 中的电子有效质量

中红外光学霍尔效应测量用于确定无意掺杂的纤锌矿结构 $c$ 面取向 In$_{0.33}$Ga$_{0.67}$N 外延层的自由电荷载流子参数。室温电子有效质量参数 $m^{*}_{\bot}=(0.205 \pm 0.013)~m_0$ 和 $m^{*}_{\parallel}=(0.204 \pm 0.016)~m_0$分别确定垂直和平行于 $c$ 轴的极化。获得的自由电子浓度为 $(1.7 \pm 0.2)\times 10^{19}~$cm$^{-3}$。在我们的不确定性范围内，我们没有检测到电子有效质量参数的各向异性，我们估计可能的有效质量各向异性的上限为 7$\%$。我们讨论了能带非抛物线对作为 In 含量函数的电子有效质量参数的影响。当包括 InN 中的强非抛物线时，有效质量参数与 GaN 和 InN 中导带质量参数之间的线性插值方案一致。发现 In$_{0.33}$Ga$_{0.67}$N 电子迁移率参数是各向异性的，支持先前对纤锌矿结构 GaN、InN 和 Al$_{x}$Ga$_{1- x}$N 外延层具有 $c$ 平面生长方向。