Ab initio calculation of optical absorption and reflectivity of Si(0 0 1)/SiO2 superlattices with varying interfaces

Using first-principles calculations we investigate the influence of interface modification and layer thicknesses on the optical properties of Si/SiO2 superlattices. Four interface models with different dangling-bond passivation are considered. The results demonstrate confinement effects not only for the fundamental band gaps but also for the optical properties. While for a large Si layer thickness of the Si/SiO2 superlattices the interface dependence is small, the calculations show a significant structure dependence for thin Si layers. © 2007 Elsevier Science. All rights reserved.