Radiative relaxation in oligosilane aggregates

Dynamical fluorescence properties of permethyldecasilane, CH3[Si(CH3)(2)](1 0)CH3, doped in 3-methylpentane glass matrices at various concentrations we re investigated by means of subnanosecond time-resolved fluorescence spectr oscopy. Two spectral components were resolved by fitting analysis of the fl uorescence spectra, yielding decay lifetimes and the time constants of temp oral shift for each resolved peak. For the higher-energy component, the pea k position was found to be independent of the concentration with its fluore scence lifetime changing slightly. For the lower-energy component, in contr ast, the amount of red-shift of the fluorescence peak became larger with in creasing the concentration while its fluorescence lifetime was also strongl y concentration dependent. These results are discussed in terms of the form ation of H-aggregates of oligosilane molecules in the glass matrices. (C) 2 000 Elsevier Science B.V. All rights reserved.