We report the electrical properties of 60° dislocations originating from the +1.2% lattice mismatch between an unintentionally doped, 315 nm thick Ge0.922Sn0.078 layer (58% relaxed) and the underlying Ge substrate, using deep level transient spectroscopy. The 60° dislocations are found to be split into Shockley partials, binding a stacking fault. The dislocations exhibit a band-like distribution of electronic states in the bandgap, with the highest occupied defect state at ∼EV + 0.15 eV, indicating no interaction with point defects in the dislocation's strain field. A small capture cross-section of 1.5 × 10−19 cm2 with a capture barrier of 60 meV is observed, indicating a donor-like nature of the defect-states. Thus, these dislocation-states are not the source of unintentional p-type doping in the Ge0.922Sn0.078 layer. Importantly, we show that the resolved 60° dislocation-states act as a source of leakage current by thermally generating minority electrons via the Shockley-Read-Hall mechanism.We report the electrical properties of 60° dislocations originating from the +1.2% lattice mismatch between an unintentionally doped, 315 nm thick Ge0.922Sn0.078 layer (58% relaxed) and the underlying Ge substrate, using deep level transient spectroscopy. The 60° dislocations are found to be split into Shockley partials, binding a stacking fault. The dislocations exhibit a band-like distribution of electronic states in the bandgap, with the highest occupied defect state at ∼EV + 0.15 eV, indicating no interaction with point defects in the dislocation's strain field. A small capture cross-section of 1.5 × 10−19 cm2 with a capture barrier of 60 meV is observed, indicating a donor-like nature of the defect-states. Thus, these dislocation-states are not the source of unintentional p-type doping in the Ge0.922Sn0.078 layer. Importantly, we show that the resolved 60° dislocation-states act as a source of leakage current by thermally generating minority electrons via the Shockley-Read-Hall mechanism.

中文翻译：

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应变弛豫 GeSn 中扩展缺陷的电学特性

我们使用深能级瞬态光谱报告了源自无意掺杂的 315 nm 厚 Ge0.922Sn0.078 层（58% 松弛）和下面的 Ge 衬底之间的 +1.2% 晶格失配的 60° 位错的电学特性。发现 60° 位错被分裂成肖克利部分，绑定了一个堆垛层错。位错在带隙中表现出带状电子态分布，最高占据的缺陷态为~EV + 0.15 eV，表明与位错应变场中的点缺陷没有相互作用。观察到捕获势垒为 60 meV 的 1.5 × 10−19 cm2 的小捕获截面，表明缺陷态的类施主性质。因此，这些位错状态不是 Ge0.922Sn0.078 层中无意 p 型掺杂的来源。重要的，我们展示了解析的 60° 位错状态通过通过肖克利-读取-霍尔机制热产生少数电子而充当泄漏电流的来源。我们报告了 60° 位错的电学特性，该位错源自 60° 位错之间的 +1.2% 晶格失配。无意掺杂的 315 nm 厚 Ge0.922Sn0.078 层（松弛 58%）和下面的 Ge 衬底，使用深能级瞬态光谱。发现 60° 位错被分裂成肖克利部分，绑定了一个堆垛层错。位错在带隙中表现出带状电子态分布，最高占据的缺陷态为~EV + 0.15 eV，表明与位错应变场中的点缺陷没有相互作用。观察到 1.5 × 10−19 cm2 的小捕获截面，捕获势垒为 60 meV，表明缺陷状态的施主性质。因此，这些位错状态不是 Ge0.922Sn0.078 层中无意 p 型掺杂的来源。重要的是，我们展示了解析的 60° 位错状态通过通过肖克利-读取-霍尔机制热产生少数电子而充当泄漏电流的来源。