"Electronic and optical properties of Si-capped and Ge-capped nanocrystallites",
L.E. Ramos, J. Furthmüller, and F. Bechstedt,
Physics, Chemistry And Application of Nanostructures: Reviews And Short
Notes to Nanomeeting 2005, V.E. Borisenko, S.V. Gaponenko, and V.S. Gurin (Editors), World Scientific Publishing Company (2005), p.66.

We present a study of the electronic structure and optical absorption spectra of Si(Ge)-capped Ge(Si) nanocrystallites (NC’s) by means of ab initio pseudopotential plane-wave calculations. In certain aspects the capped Si(Ge) NC’s are similar to the analogous Si/Ge heterojunctions. A compensation effect involving the overall composition of the nanocrystallite and quantum confinement effects is predicted for the Si-capped Ge NC’s.