III-V quantum dot lasers grown on patterned silicon and SOI substrates by MBET first year

点击翻译按钮获取中文摘要

There is a strong demand for integrating of III-V materials and devices on silicon platform for high-efficient photonics light sources and high mobility electronics devices. However, there are significant challenges for direct epitaxial growth, including anti-phase boundaries (APBs), threading dislocations (TDs) and micro-cracks. In last few years, significant progress has been made in reducing these three types of defects with a few micrometre III-V buffer layers. In addition, the total thickness of III-V layers is limited to a few micrometres (< 6um) by the formation of micro-cracks due to a mismatch in thermal expansion between the III-V epilayers and a Si substrate. In this project, we will exploit the potential of patterned silicon to suppress the defect formation within the patterned area on Si or SOI substrates. Most importantly, we would like to grow nano-size holes within the patterned areas by grow group-IV materials, such as Si and Ge by using twin-MBE system at UCL to relax the strain between III-V layers and silicon substrates, and hence to solve the problem due to thermal expansion mismatch between III-V layers and silicon substrates.