Photoluminescence and Raman study of a tensilely strained Si type-II quantum well on a relaxed SiGe graded buffer

Abstract

We have investigated the photoluminescence and Raman scattering of tensilely strained Si quantum wells embedded in Si1−xGex relaxed layers. The radiative recombination of excitons in the Si1−xGex (x ≲ 0.3) alloy layers and the type II transitions involving the recombination of an electron localized in the Δ2 minimum of the conduction band of the strained Si quantum well and a hole localized in the valence band maximum of the Si1−xGex layer were observed. The influence of a graded buffer on the density of defects/dislocations and, consequently, on the optical properties was clearly observed.