(Digital Presentation) Fabrication of Thick SiGe／Ge Multiple Quantum Wells on Ge-on-Si and Their Optical Properties

We fabricate thick strained Si0.1Ge0.9/Ge multiple quantum wells (MQWs) structures on Ge-on-Si, and evaluate their crystallinities and optical properties. As a result, it is found that highly crystalline Si0.1Ge0.9/Ge MQWs are grown both on Ge-on-Si(100) or Ge-on- Si(111), where surface roughness slightly differs between the two. From both MWQs we obtain strong room-temperature photoluminescence (PL) via quantum confinements of carriers in the MQWs. It is also found that the PL peak positions and intensities are different between (100) and (111). Surface roughening is considered to cause reduction in the PL intensity and the peak shift for the (111) case whereas the MQWs on Ge-on-Si(100) shows very smooth surface and resultantly strong PL intensity, indicating that Si0.1Ge0.9/Ge MQWs are promising for applications to light-emitting devices that can be integrated on the Si platform.