Silicon-rich oxide/silicon dioxide , , superlattice thin films, deposited by the radio-frequency magnetron-sputtering technique, was rapid thermal annealed at temperatures ranging from . The photoluminescence (PL) spectra of samples after rapid thermal annealing (RTA) at consists of oxygen-deficiency-related PL bands around and , and silicon (Si) nanocrystal-related PL bands around . Absorption bands at and are considered to be related to Si nanocrystals. On the basis of PL and PL excitation spectra, an energy-band diagram of a RTA-treated superlattice sample was constructed.