Observation of confined electronic states in GexSi1−xSi strained-layer superlattices

Abstract

We used resonant Raman scattering to probe into the electronic states of ${\mathrm{Ge}}_{\mathrm{x}}$ ${\mathrm{Si}}_{1\mathrm{-}\mathrm{x}}$Si strained-layer superlattices. Resonant enhancements are observed in the cross section of Raman lines originating in vibrational modes of the alloy layers but do not occur in the cross section of the Si line. This shows that the electronic states being probed are confined within the alloy quantum wells. Confinement is also shown by the dependence of the energy of these states on the width of the wells.