Size-dependent correlation of the photoluminescence lifetime with Si suboxide states at si nanocrystal/SiO2 interfaces

作者：Kim Sung; Choi Suk Ho^*

来源：Journal of the Korean Physical Society, 2008, 52(2): 462-465.

• Si nanocrystal
• photoluminescence lifetime
• Si suboxide states
• size effect

Double layers of 28 nm SiOx/2 nm SiO2 have been prepared on Si wafers by ion beam sputtering deposition and subsequently annealed to form Si nanocrystals (NCs) in the SiOx layer. The photoluminescence (PL) lifetime obtained by fitting the decay traces to a stretched exponential function shows a sharp decrease as the NC size (d) is reduced down to similar to 3 nm, but below similar to 3 nm, its rate of decrease slows down. This phenomenon is strongly related to the change in Si suboxide states at the Si NC/SiO2 interfaces, as confirmed by synchrotron-radiation X-ray photoelectron spectroscopy spectra of the Si 2p core level for the Si NC layers. These results can be explained based on the fact that as d decreases, the PL decays are increasingly influenced by interface states such as Si-O or Si=O bonds.

• 出版日期2008-2