ABSTRACT
Si-Ge superlattices (SL) are of particular interest due to the possibility of creating a direct band gap in the Si-based system. This chapter discusses the formation of a SiGe-SL generated by molecular beam epitaxy. Specific growth parameter where chosen to optimise the periodic layers of the SL, which consists of vertically stacked islands. SL exhibits light emission at a wavelength of about 1.5 /Jill at up to room temperature. Several attempts have been made to increase the low radiation efficiency and to create Si-based optical devices. Promising results were achieved by applying nanostructures in a Si matrix, such as nanoparticles, quantum wells and quantum dots. Molecular beam epitaxy (MBE) is a successful growth technique to generate such SiGe-SL structures. Measurements of the photoluminescence intensity demonstrated the strong dependence of the luminescence on MBE growth parameters, such as composition, period length, and the growth temperature.
