Valence band offset at the Si/SiSn interface by applying deep level transient spectroscopy.

A set of Si1−x Sn x /Si(001) quantum wells (QWs) is grown by applying molecular beam epitaxy. The activation energies of holes in these QWs are studied by deep-level transient spectroscopy. It is observed that the holes activation energies increase monotonically with the Sn fraction (x). The valence band offset between pseudomorphic Si1−x Sn x and Si obeys the dependence = 1.69x eV, while the offset between the average valence bands of unstrained Si1−x Sn x /Si heterojunction was deduced and obeys the dependence = 1.27x eV.