Optical properties of silicon nanocrystallites in SiO2 matrix: Crystalline vs. amorphous case

Within a first-principles framework we show the dependence of the optical properties of silicon nanocrystallites embedded in a silica matrix on the crystalline vs. amorphous order of the system. Moreover we calculate how many-body effects modify the electronic and optical properties of the embedded silicon nanodots. A discussion about the different roles played by dimensionality, interface properties, disorder and excitonic effects on the electronic and optical properties of the confined nanostructures is presented.