• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nanotechnology >Photoluminescence investigation of strictly ordered Ge dots grown on pit-patterned Si substrates
【24h】

Photoluminescence investigation of strictly ordered Ge dots grown on pit-patterned Si substrates

机译：在点蚀图案化的Si衬底上生长的严格有序的Ge点的光致发光研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We investigate the optical properties of ordered Ge quantum dots (QDs) by means of micro-photoluminescence spectroscopy (PL). These were grown on pit-patterned Si(001) substrates with a wide range of pit-periods and thus inter QD-distances (425-3400 nm). By exploiting almost arbitrary inter-QD distances achievable in this way we are able to choose the number of QDs that contribute to the PL emission in a range between 70 and less than three QDs. This well-defined system allows us to clarify, by PL-investigation, several points which are important for the understanding of the formation and optical properties of ordered QDs. We directly trace and quantify the amount of Ge transferred from the surrounding wetting layer (WL) to the QDs in the pits. Moreover, by exploiting different pit-shapes, we reveal the role of strain-induced activation energy barriers that have to be overcome for charge carriers generated outside the dots. These need to diffuse between the energy minimum of the WL in and between the pits, and the one in the QDs. In addition, we demonstrate that the WL in the pits is already severely intermixed with Si before upright QDs nucleate, which further enhances intermixing of ordered QDs as compared to QDs grown on planar substrates. Furthermore, we quantitatively determine the amount of Ge transferred by surface diffusion through the border region between planar and patterned substrate. This is important for the growth of ordered islands on patterned fields of finite size. We highlight that the Ge WL-facets in the pits act as PL emission centres, similar to upright QDs.
机译：我们通过微光致发光光谱法（PL）研究有序Ge量子点（QDs）的光学性质。将它们生长在具有宽范围的凹坑周期的凹坑图案化Si（001）衬底上，从而实现QD间距（425-3400 nm）。通过以这种方式利用几乎可以实现的任意QD间距离，我们能够在70至少于三个QD的范围内选择有助于PL发射的QD数量。这个定义完善的系统使我们可以通过PL研究来澄清一些要点，这些要点对于理解有序QD的形成和光学性质非常重要。我们直接跟踪和量化从周围的润湿层（WL）转移到坑中的量子点的Ge的数量。此外，通过利用不同的凹坑形状，我们揭示了应变诱导的激活能垒的作用，对于点外生成的电荷载流子必须克服。这些需要在凹坑中和凹坑之间的WL最小能量与QD中的最小能量之间扩散。此外，我们证明了凹坑中的WL在直立的QD形核之前已经与Si严重混合，与在平面基板上生长的QD相比，这进一步增强了有序QD的混合。此外，我们定量地确定了通过表面扩散穿过平面基板和已图案化基板之间的边界区域而转移的Ge的数量。这对于在有限大小的图案化字段上生长有序岛非常重要。我们强调指出，凹坑中的Ge WL面可作为PL发射中心，类似于直立的QD。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号