Specific Features of Lluminescence of Oxygen-Deficient Centres in Nanostructured Silicon Dioxide

Abstract

Specific features of radiative and non-radiative relaxations of oxygen-deficient centres (ODC's) in nanostructured silicon dioxide were studied using optically stimulated electron emission and time-resolved photoluminescence. It was found that modifications of oxygen-deficient centres in the form of surface analogues can exist in nanostructured samples prepared by thermal decomposition of polysilazane in air. Photoluminescence of these centres was efficiently excited in the optical absorption bands of surface Es′-centres and silicon clusters {triple bond, long} SiSiSi {triple bond, long} and could be associated with the intercentre energy transfer during their nonradiative relaxation. Specific features of thermally induced changes in the luminescence characteristics of the defects due to transformation of the structure of silica samples from amorphous to partially crystalline modification were established from analysis of the spectral composition and the decay kinetics of the photoluminescence. © 2007.This study was supported by RFBR (Projects Nos. 04-02-96073, 05-02-16448 and 05-02-16530) and the RF Ministry of Education (Project RNP.2.1.1.2948)