Effect of Ge deposition rate on growth and optical properties of Ge(Si)/Si(001) self-assembled islands

In this paper we study the growth and photoluminescence spectra of GeSi/Si(001) self-assembled islands grown in wide range of Ge deposition rate (ν_Ge=0.1÷0.75 Å/s). AFM studies of these structures revealed that for all Ge growth rates the dominant island species is the dome-shaped islands. It was found that the lateral size of dome islands is decreased and their surface density is increased with increasing of ν_Ge. The decreasing of the lateral size is connected to increasing of Ge content in islands and part of surface occupied by the islands. The red-shift of the island related photoluminescence peak was observed during the island Ge growth rate increasing. This shift is associated with increasing of Ge content in islands.