Abstract Epitaxial growth of III-V heterostructures on non-native substrates such as Silicon (Si) or Germanium (Ge) is one of the promising research topics for the last two decades. The interface between polar III-V semiconductors and non-polar substrates (Si or Ge) plays a crucial role in monolithic integration. However, there is an anticipation of epitaxial GaAs growth on Ge substrate because of the lower mismatch of lattice constants and thermal expansion coefficients between them. Therefore, the high-quality growth of III-V semiconductor heterostructures on Ge substrates would overcome the impediment to Si-photonics, where the monolithic integration of optoelectronic device structures can be done using a Ge graded layer on Si. Here, we have explored the epitaxial growth of multi-layer InGaAs/GaAs quantum dot heterostructures on Ge substrates and compared the optical and structural properties with the QDs grown on GaAs substrate. The optical properties of all samples are investigated with the help of photoluminescence (PL) and time-resolved photoluminescence (TRPL), whereas the morphology of the QDs is observed through cross-sectional transmission electron microscopy (XTEM) images. An enhancement in the optical characteristics (PL peak wavelength, activation energy, carrier lifetime) is found for the QDs grown on Ge substrate with the super-lattice buffer (SLB) layer. The minimization of defects and dislocations in the heterostructure is also realized for the structure with the SLB layer. Furthermore, a two-fold enhancement in PL intensity and 24 meV increment in activation energy is achieved through ex-situ H− ion-implantation, which approached the values obtained for the QD heterostructure grown on GaAs substrate.

中文翻译：

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通过异位离子注入在Ge衬底上实现高质量的InGaAs/GaAs量子点生长和提高光学性能

摘要 在硅 (Si) 或锗 (Ge) 等非原生衬底上外延生长 III-V 族异质结构是过去二十年有前途的研究课题之一。极性 III-V 族半导体和非极性衬底（Si 或 Ge）之间的界面在单片集成中起着至关重要的作用。然而，由于它们之间的晶格常数和热膨胀系数的失配较低，因此预计在 Ge 衬底上外延 GaAs 生长。因此，在 Ge 衬底上高质量生长 III-V 族半导体异质结构将克服 Si 光子学的障碍，其中可以使用 Si 上的 Ge 渐变层完成光电子器件结构的单片集成。这里，我们探索了 Ge 衬底上多层 InGaAs/GaAs 量子点异质结构的外延生长，并将其光学和结构特性与生长在 GaAs 衬底上的 QD 进行了比较。借助光致发光 (PL) 和时间分辨光致发光 (TRPL) 研究所有样品的光学性质，而通过横截面透射电子显微镜 (XTEM) 图像观察 QD 的形态。发现在具有超晶格缓冲 (SLB) 层的 Ge 衬底上生长的 QD 的光学特性（PL 峰值波长、活化能、载流子寿命）增强。对于具有 SLB 层的结构，还实现了异质结构中缺陷和位错的最小化。此外，