Many types of nanocrystals are under investigation for variety of applications ranging from optics to sensing. In our group, Si, Ge and SiGe nanocrystals in oxide and nitride matrices are being investigated for memory and solar cell applications. Plasma enhanced chemical vapor deposition is used to deposit oxide or nitride layers rich in the element intended for nanocrystal formation. High temperature furnace treatment as well as rapid thermal annealing is used to precipitate defect free nanocyrstals. Such materials are studied with transmission electron microscopy, Raman scattering, atomic force microscopy. In a recent collaborative work with FZD-Dresden and METU we are now studying the formation of nanocrystals using high power lasers for applications in solar cells.