The electronic and optical properties of Si/SiO2 superlattices: Role of confined and defect states

The Si layer thickness dependence of the optical properties of silicon/silicon dioxide (Si/SiO2) superlattices has been,for the ®rst time, theoretically investigated. In our ®rst principle calculation we consider both fully passivated interfacesand the presence of oxygen vacancy at the interface. Our results show the key role played both by the quantum con®nedstates and interface states in the experimentally observed visible luminescence in Si/SiO2 con®ned systems.