Intersubbband absorption in narrow Si/SiGe multiple quantum wells without interfacial smearing

Abstract

Si/Si1−xGex multiple quantum wells with abrupt heterointerfaces have been formed by segregant-assisted growth (SAG) with Sb. Distinct well-width dependence of intersubband absorption in the narrow quantum wells has been observed. The well-width dependence of the absorption peak energy is in good agreement with a calculation based on the Kronig–Penney model where interfacial smearing is taken to be less than 0.4 nm, suggesting the integrity of Si/Si1−xGex interfaces grown by SAG.