Ge self-assembled islands grown on SiGe/Si(0 0 1) relaxed buffer layers

In this work, the results obtained in growth of Ge(Si) self-assembled islands on relaxed Si1−xGex/Si(0 0 1) buffer layers (x ∼ 25%) and their photoluminescence study are presented. It is found out that growth of Ge(Si)/Si1−xGex islands proceeds with an abrupt change in the surface morphology that is similar to the earlier observed transition (from dome to hut islands with a decreasing Ge growth temperature) in the case of island growth on Si(0 0 1) substrates. It is revealed that in growth of Ge(Si)/Si1−xGex islands, in contrast to the Ge(Si)/Si(0 0 1) islands case, the interval of growth temperatures, in which there is a change in the islands morphology (dome–hut transition) shifts towards higher temperatures. For the first time a photoluminescence signal from Ge(Si) self-assembled islands embedded in a strained Si layer is observed.