Optical transition in SiGe self-organized dots

Abstract
It is found that the SiGe alloy self-organizers into uniform quantum dots embedded in the Si layer during the growth of a strained Si/Ge short period superlattice on a Si(001) substrate at a temperature of 800 °C by molecular beam epitaxy. The peak of photoluminescence from the quantum dots is at an energy higher than the band gap of Si. The intensity is two orders of magnitude higher than that of SiGe/Si quantum well.